Produce an auditable financial model for one product and marketplace. Separate known costs from assumptions, calculate a base case, and show how the decision changes under plausible scenarios.
The included zero-third-party-dependency calculator applies explicit per-unit and first-order formulas. It is a planning model, not accounting, tax, or investment advice.
| Dependency | Required | Validation | Fallback |
|---|---|---|---|
| Python 3.10+ | Optional | Run python scripts/unit_economics.py --help |
Calculate with the documented formulas and label manual work |
| Price and cost assumptions | Yes | Values are numeric, non-negative, and currency-consistent | Return the missing-assumption list |
| Marketplace fee basis | Yes for Amazon margin | User-supplied current fee or documented estimate | Do not infer a current fee |
| Demand and payment timing | Conditional for cash flow | Units, lead time, deposit, balance, and replenishment timing are explicit | Limit output to per-unit economics |
Provide JSON with the fields documented by scripts/unit_economics.py --example. Required fields are selling price, referral fee, fulfillment fee, landed product cost, return rate, return loss per returned unit, advertising ACOS, and other variable cost. First-order cash analysis additionally needs order units, tooling, setup costs, deposit rate, and working-capital buffer.
Use one currency per run. Percentages are decimals from 0 to 1. Record the source and date of marketplace fees separately in the surrounding evidence bundle. Prices, quotes, and internal margins may be sensitive.
The calculator returns JSON containing revenue after returns, Amazon fees, expected return loss, advertising cost, contribution profit and margin, break-even ACOS, first-order cash requirement, and scenario results. It writes to stdout or an explicitly selected file and performs no network or account actions.
Success requires that inputs pass validation, formulas reconcile, units and currency are stated, and the output distinguishes per-unit profitability from inventory cash. Invalid input returns a non-zero exit code without partial financial claims.
scripts/unit_economics.py.INSUFFICIENT_EVIDENCE when a critical fee or cost is missing.python scripts/unit_economics.py --example > assumptions.json
python scripts/unit_economics.py assumptions.json --pretty
0..1, or inconsistent currency: fail validation.python -m unittest discover -s tests -v passes for the bundled calculator.