THE METHODS · THE STUDIO ROOM · Nº 429 · EDITION 2 · LAUNCHING SOON

LUND CARDS · THE METHODSNº 429

THE CARD AS TEXT · FOR EYES AND FOR MACHINES

THE PRICE CARD · The figure seat: a price built from its cost and its margin, arithmetic shown, never a guess.

WAKES WHEN Someone is about to set a price and has only a feeling for the cost. · A price list has drifted and nobody knows which lines still clear their cost. · A margin ladder is wanted: the same item at three margins, rounded the house's way. · A supplier's figure changed and every price that rests on it needs re-checking.

THE LOOP

Build the unit cost from the bill of parts
Ladder it at the margins the house names
Check the list: BELOW COST and THIN named
Show the arithmetic beside every figure

NEVER

Never invents a market price
Never prices an item with no cost on file
Never hides a margin below the floor
Never claims a certainty it does not have

IT MAKES cost — the unit cost of each item, sum of cost × qty_per_item, every part line printed and then the total; an item named with no parts is NO COST ON FILE (exit 1); ladder — the price at each margin in the rule, cost / (1 - margin/100), rounded the rule's way, the formula printed beside every figure; NO COST ON FILE (exit 1) for an item with no parts; check — every priced item's margin, (price - cost) / price: BELOW COST under its cost, THIN under the floor margin, NO COST ON FILE with no parts; nothing is hidden; exit 1 if any BELOW COST; compare — the person's price beside each figure they brought, with the difference and the percent of their own price; NO FIGURES BROUGHT for an item with none; the machine knows no market; moved — the priced items whose cost or margin changed between the previous parts sheet and this one, old and new, with the new margin judged against the floor.

THE LAW A price is arithmetic on a cost the person supplied; it is never a guess at what a market will bear. Every figure the machine prints carries the cost and the margin it came from. An item with no cost on file is NO COST ON FILE, and nothing is priced on its behalf.

IN THE BOX SKILL.md · CARD.md · ▣ scripts/price.py (machine) · ▣ scripts/evals.py (test runner) · tests/EVALS.json (9 tests) · references/ (schema + fictional demo) · START-HERE.md · system/ doors · MY-LEDGER.md · LICENSE-NOTE.md · card.svg · card.json · card.html · AUDIT.md · MANIFEST.md · WITNESS.md · SELFTEST.md.

PROOF SELFTEST 15/15 · witnessed in Claude 2026-10-14 on fictional fixtures · the test prompts in fresh chat, 9/9 · Edition 2.

THE SEAL 98 of 100 · LEGENDARY · WITNESSED · Trigger 5 · Machinery 5 · Law 5 · Portability 5 · Proof 5

IT CAN BE WRONG an AI reading a text file: it can be wrong and can invent a number, a rule, a name or a date; check what matters against your own records and the source; the risk is yours. LICENSE-NOTE.md rides in the packet and is the licence.

THE PUNCH · SHA-256 OF SKILL.MD · BD1BA9095360636E0CAA1842

THE FACE, FULL SIZE → · THE MACHINE FACE → · card.json →

THE PRICE CARD

The figure seat: a price built from its cost and its margin, arithmetic shown, never a guess.

COST · LADDER · CHECK · COMPARE · MOVED

LEGENDARYWITNESSEDIN CLAUDE IN LUNDR IN CHATGPT

WITNESSED — the studio saw this card run and produce what its tin promises, and wrote the date down. What the marks mean →

THE SPEC SHEET · READ BEFORE YOU BUY · THE STANDARD EVERY CARD MEETS →

SEAL: 98 of 100 · LEGENDARY · WITNESSED
EDITION: E1 · witnessed 2026-10-14
MACHINE: scripts/price.py · 5 commands · selftest 15/15
RUNS: On your own computer. Standard library only, offline; no account, no key, no telemetry.
HOSTS: Claude · Claude Code · ChatGPT · Gemini · any AI that reads a file (START-HERE.md and system/ name each door)
LICENCE: One person, any number of their own AIs and computers · editions replace files · nothing renews · freeze, not loss
PUNCH: BD1BA9095360636E0CAA1842 · sha-256 of SKILL.md · check any file against it →

CITE THIS CARDTHE PRICE CARD, Edition 2. Lund Studio LLC, Westminster, Colorado. https://lundr.tech/?view=price-card. Punch BD1BA9095360636E0CAA1842. Retrieved 2026-10-14.

What it is.

Use when a price must be set or checked from its own cost sheet: unit cost, a margin ladder, a check of a price list. Not for guessing what a market pays or for tax or legal advice.

It carries a machine that shows its working: cost — the unit cost of each item, sum of cost × qty_per_item, every part line printed and then the total; an item named with no parts is NO COST ON FILE (exit 1); ladder — the price at each margin in the rule, cost / (1 - margin/100), rounded the rule's way, the formula printed beside every figure; NO COST ON FILE (exit 1) for an item with no parts; check — every priced item's margin, (price - cost) / price: BELOW COST under its cost, THIN under the floor margin, NO COST ON FILE with no parts; nothing is hidden; exit 1 if any BELOW COST; compare — the person's price beside each figure they brought, with the difference and the percent of their own price; NO FIGURES BROUGHT for an item with none; the machine knows no market; moved — the priced items whose cost or margin changed between the previous parts sheet and this one, old and new, with the new margin judged against the floor — 15 checks in its selftest. It never invents a market price; never prices an item with no cost on file; never hides a margin below the floor; never claims a certainty it does not have.

The law, written into the card.

It is in the card itself, so the AI follows it.

THE LAWA price is arithmetic on a cost the person supplied; it is never a guess at what a market will bear. Every figure the machine prints carries the cost and the margin it came from. An item with no cost on file is NO COST ON FILE, and nothing is priced on its behalf.

The method.

Lay the bill of parts in a sheet: each part, its cost, its unit and how many go into one item; the unit cost is their sum, printed with every line it came from.
Ladder the unit cost at the margins the house names (say 30, 45 and 60 percent) and round by the house's own rounding rule; the rule is printed with the figures.
Check a price list against the costs: a price under its cost is BELOW COST; one under the house's floor margin is THIN; an item with no cost line is NO COST ON FILE.
Compare against figures the person brought (their own list of what others charge) and only those; the machine never reaches for a market figure of its own.
When a part's cost changes, rerun the check; every price that moved is listed with its old and new margin.

What you bring.

The bill of parts with each cost, in the person's own currency.
The margins the house wants and its rounding rule.
The price list to check, if there is one.

Planned as a separate seat, not in this box and not yet on sale: the studio's own cost sheets for its goods and cards.

What it does once your AI has it.

cost The unit cost of each item, sum of cost × qty_per_item, every part line printed and then the total; an item named with no parts is NO COST ON FILE (exit 1)
ladder The price at each margin in the rule, cost / (1 - margin/100), rounded the rule's way, the formula printed beside every figure; NO COST ON FILE (exit 1) for an item with no parts
check Every priced item's margin, (price - cost) / price: BELOW COST under its cost, THIN under the floor margin, NO COST ON FILE with no parts; nothing is hidden; exit 1 if any BELOW COST
compare The person's price beside each figure they brought, with the difference and the percent of their own price; NO FIGURES BROUGHT for an item with none; the machine knows no market
moved The priced items whose cost or margin changed between the previous parts sheet and this one, old and new, with the new margin judged against the floor

What it will never do.

It never invents a market price; never prices an item with no cost on file; never hides a margin below the floor; never claims a certainty it does not have.

Where it hands off: Ranking several offers against each other → THE BOARD CARD; Writing the price onto the store page → the store's own tools; Tax on a sale → a tax professional.

It is not tax, legal or financial advice. It is an AI reading a text file: it can be wrong, so check what matters against your own records and the source. The holder brings their own AI; no endorsement by Anthropic or any other AI company is claimed.

What’s in the buy.

SKILL.md — the card your AI reads: when it wakes, the loop, the never-lines, the hand-offs.
CARD.md — the whole card in ten sections: face, law, method, machine, what you bring, never, tests, seal, term.
scripts/price.py — the machine, Python standard library only; `selftest` proves it on its own fixtures.
tests/EVALS.json and scripts/evals.py — 9 test prompts and the offline runner that scores your AI's answers.
references/ — the data schema and FICTIONAL demo files, invented to show the machine, not real.
MY-LEDGER.md — your own record of what you asked and what you decided.
START-HERE.md, system/short-prompt.md, system/rules.md — the doors, for any AI with or without skills.
card.svg, card.json, card.html, AUDIT.md, MANIFEST.md, WITNESS.md, SELFTEST.md — the faces and the proof.
NOT IN THE BOX — any studio edition (planned, not yet on sale: the studio's own cost sheets for its goods and cards). Also not in the box: any data you must bring, and advice of any kind (not tax, legal or financial advice).

PROOF · SELFTEST 15/15 · WITNESSED IN CLAUDE 2026-10-14 ON FICTIONAL FIXTURES · THE 9 TEST PROMPTS ASKED IN A FRESH CHAT HOLDING ONLY THE CARD · 9/9 · EDITION 2 · PUNCH BD1BA9095360636E0CAA1842

ON EVERY DOOR · A CARD FOR YOUR AI, A FILE FOR YOUR COMPUTER

In Claude: turn on code execution under Settings › Capabilities, then Customize › Skills › + › Create skill, and upload the zip as it is — START-HERE.md in the box walks you through it, and tells you how to keep the ledger. In ChatGPT, Gemini and the rest: a Project, a GPT or a Gem with the card’s files attached and the short door in the box pasted as its instructions. The words run anywhere an AI reads Markdown; the machines run wherever the host runs Python. Witnessed in Claude only. The host marks →

Take it.

Nº 429 — LAUNCHING SOON

Sold as is under the term printed. A card instructs an AI you operate; results depend on your model, your files and your judgement. Not medical, legal, tax or financial advice, never the person’s boss, and not a licence to practise. The terms →

ONE PAYMENT · NOTHING RENEWS ITSELF

OFFLINE · ONE LICENCE · PUNCH-CHECKABLE · THE STANDARD

One payment. The file is yours to keep and keeps working at its edition; new editions issued in the year after you buy reach you by email as replacement files. Tax is added at checkout where it applies. Nothing auto-renews.

A TERM, NOT A SUBSCRIPTION: NOTHING RENEWS ITSELF AND NOBODY IS CHARGED AGAIN. WHEN A TERM ENDS THE FILES STAY ON YOUR COMPUTER AND STAY READABLE — FREEZE, NOT LOSS.

THE MACHINE · IN THE OPEN · FROM THE CARD’S OWN SELFTEST.MD

price.py, every command showing its working.

A small Python program, standard library only. Your AI runs it; you can too. The block below is pasted from the card’s own SELFTEST.md, as printed when it was run from inside the packet.

`cost`	the unit cost of each item, sum of cost × qty_per_item, every part line printed and then the total; an item named with no parts is NO COST ON FILE (exit 1)
`ladder`	the price at each margin in the rule, cost / (1 - margin/100), rounded the rule's way, the formula printed beside every figure; NO COST ON FILE (exit 1) for an item with no parts
`check`	every priced item's margin, (price - cost) / price: BELOW COST under its cost, THIN under the floor margin, NO COST ON FILE with no parts; nothing is hidden; exit 1 if any BELOW COST
`compare`	the person's price beside each figure they brought, with the difference and the percent of their own price; NO FIGURES BROUGHT for an item with none; the machine knows no market
`moved`	the priced items whose cost or margin changed between the previous parts sheet and this one, old and new, with the new margin judged against the floor
`selftest`	15 checks that prove the machine; it must print selftest 15/15

THE SELFTEST, AS PRINTED

ok   1  cost prints every part line and the unit cost as the sum of cost × qty (9.30 from three parts)
ok   2  cost for an item with no parts is NO COST ON FILE: refused (exit 1), no figure invented
ok   3  a cost that is not a number is bad input (exit 2)
ok   4  ladder prices at each margin with the formula, rounded to the whole by the rule (13, 17, 23)
ok   5  ladder follows the rounding rule: tenth 23.3 (half up), hundredth 23.25, none shown to six places
ok   6  ladder for an item with no parts refuses NO COST ON FILE (exit 1)
ok   7  a rule with a margin of 100 or more, or a rounding it does not know, is bad input (exit 2)
ok   8  check names BELOW COST for a price under its cost and exits 1
ok   9  check names THIN under the floor and NO COST ON FILE for an item with no parts; every priced item is printed, none hidden
ok   10  check exits 0 when nothing is below cost, with THIN still printed as a flag
ok   11  compare says 'Figures brought by the person; the machine knows no market' first and prints each brought figure with the difference and percent of the person's price
ok   12  compare prints NO FIGURES BROUGHT for an item with no theirs row and never reaches for a market figure
ok   13  moved lists the priced items whose cost changed with old and new cost and margin, and names the unchanged ones
ok   14  the currency is a code of letters printed after the figure, never a symbol: a symbol is bad input (exit 2), eur prints as EUR
ok   15  a prices file without the columns item, price is bad input (exit 2)
selftest 15/15

THE RUN IS PASTED FROM THE CARD’S OWN SELFTEST.MD AS PRINTED. ITS FIXTURES ARE FICTIONAL, INVENTED FOR THE TEST; NO PRIVATE PERSON IS NAMED.

QUESTIONS AT THE TABLE

Asked before the wire.

What does it need from me?

The bill of parts with each cost, in the person's own currency. The margins the house wants and its rounding rule. The price list to check, if there is one. If something it needs is missing, it says what is missing and stops there.

Does it send anything anywhere?

No. The machine is a standard-library Python program that runs on your own computer and sends nothing anywhere; the words run wherever an AI reads Markdown. No server, no account, no key.

What is on the record?

The machine's selftest (15/15), run from inside the packet in Claude on 2026-10-14 on fictional fixtures and pasted into SELFTEST.md as printed; the twelve-check audit (AUDIT.md). Owed, and said so in WITNESS.md: Any run on real data. Every demo file is fictional. The punch on the face is the SHA-256 of SKILL.md, so a downloaded copy can be checked against this room.

Can it be wrong?

Yes — it is an AI reading a text file: it can be wrong and can invent a number, a rule, a name or a date; check what matters against your own records and the source; the risk is yours. LICENSE-NOTE.md rides in the packet and is the licence. It is not tax, legal or financial advice.

What will it never do?

It never invents a market price; never prices an item with no cost on file; never hides a margin below the floor; never claims a certainty it does not have.

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