Four numbers decide whether a product is worth buying. The formulas are short, and you can try them in our calculator.
Unit profit
Selling price, minus your cost, prep, other costs and marketplace fees. Fees are the referral fee (a percentage of price) plus the fulfillment fee.
Margin
Profit divided by selling price. It tells you how much cushion a price drop leaves you.
ROI
Profit divided by everything you spent on the unit. It tells you how hard your money works.
Break-even price
The lowest price at which you lose nothing: your total unit costs plus the fulfillment fee, divided by one minus the referral percentage.
Example: $12 cost, $0.50 prep, $5.40 fulfillment and a 15% referral fee gives a break-even of about $21.06.