Reseller margin and ROI: net proceeds, not gross spread

The evaluation model

Expected net proceeds equals the recency-weighted median sale price for the matched condition grade, minus marketplace commission, payment processing, outbound shipping and any promoted-listing spend. Expected profit is net proceeds minus total landed acquisition cost and prep.

ROI is profit divided by total cash deployed, not by the purchase price alone. Financing an item that also required forty dollars of shipping and cleaning consumed forty dollars of capital.

Breakeven is a decision tool

Every evaluation reports the maximum purchase price at which the deal still clears your target margin. That single number converts a research session into a negotiating position: you know your walk-away figure before you make an offer.

Annualized return exposes slow inventory

A 25 percent return in three weeks and a 25 percent return in nine months are not comparable investments. MarginMap annualizes using observed days-to-sell for the variant, which reliably demotes high-margin, low-velocity items that look attractive on a spreadsheet and quietly consume shelf space and working capital.

Risk lines that change decisions

Thin comp samples widen the outcome range. Authentication-sensitive categories carry a return and dispute premium. Condition uncertainty at acquisition propagates into the sale-side grade and therefore the achievable price. Each of these appears as an explicit line in the evaluation rather than as a haircut buried in a coefficient.