Work backward from a sale scenario, actual fee amount and chosen profit target. A negative ceiling is a reason to stop, not negotiate harder.
Use the bench in three moves
Check product safety, permitted saleability and actual terms first.
Fill every applicable cost; keep unknown assumptions labelled, not silently zero.
Read the method and exclusions, then change one assumption to test the downside.
Read the tape
Method and boundaries
Maximum acquisition price = receipts − fees − postage − packing/preparation − repairs − chosen uncertainty allowance − chosen pre-tax profit. All amounts are for the same single-item scenario. A negative answer means no non-negative purchase price meets the target. A positive ceiling is not permission to buy: verify safety, ownership, demand, the current fee basis and your cash-at-risk limit. The allowance is your assumption, not a measured return rate or a tax deduction. Time is covered only if you deliberately include its value in your target.
Worked example · hypothetical, not an actual seller
A bargain needs a ceiling
Chosen receipts $58, selling fee $8.29, postage $8, packing $2, repair $0, uncertainty allowance $3 and desired profit $20. The $8.29 fee follows the eligible eBay illustration; all other amounts are chosen assumptions.
Maximum acquisition price $16.71. A higher buy price misses this chosen target. No buyer or lawful saleability is established.
Published US fee snapshots · checked November 8, 2026
A source check date is not a claim that the rates changed on that date. Confirm current applicability before calculating. These are seller-fee models, not total buyer checkouts.
eBay US · non-Store most categories
13.6% up to $7,500 per item; 2.35% of the excess. Plus $0.30 per order up to $10; $0.40 above $10.
Scope and omissions: Only the “Most categories” row on the non-Store US schedule. Books/media, trading cards, watches, handbags, sneakers and other exceptions may have different rates. Excludes Stores, international/currency charges, shipping-base exceptions, optional services, performance surcharges, tax on fees and multi-item orders.
10% selling fee, under the structure effective January 6, 2025.
Fee base: Item + buyer-paid shipping; not buyer sales tax.
Scope and omissions: Current US selling-fee structure, not historical unupdated listings. Buyer Protection fee is buyer-paid, not an extra seller deduction. Separate shipping adjustments, optional withdrawal/cancellation/authentication charges and other services are not inferred. Official fee page updated October 23, 2026.
Fee base: Item sale price only; do not add buyer-paid platform shipping to seller receipts.
Scope and omissions: Standard US fee, not Canada, wholesale or a temporary offer. Seller shipping discounts/upgrades and other seller-paid costs must be entered separately. The official getting-started guide explicitly puts $15 in the percentage tier.