How to track your cards' cost basis and profit

If you buy and sell cards, the price on the listing is only part of what a card cost you. Knowing the real number — your cost basis — is what lets you set a fair price and see whether a flip actually made money.

What “cost basis” means for a card

Cost basis is the total you paid to own a card: the item price plus its share of the order's shipping, any tax, and the marketplace fees. A $100 card in an order that also charged $12 shipping didn't cost $100 — it cost its slice of the whole order.

Why the sticker price misleads you

Shipping and fees are easy to forget because they arrive bundled into one order total. But when you sell, they are exactly what decides whether you came out ahead. Tracking only the sticker price makes every card look cheaper than it was, and every sale look more profitable than it was.

Working out profit when you sell

Profit is the sale price, minus the selling fees and shipping you paid, minus the cost basis. Doing that by hand across dozens of orders is where most people give up — the numbers are scattered across order confirmations and payout emails.

How My Card Inventory helps

My Card Inventory splits an order's shipping and fees across the cards in it automatically, so each card carries its true cost basis. Log a sale and it works out the profit for you. You can build it by forwarding your receipts, importing a spreadsheet, or adding cards by hand.