A card selling for more than you paid does not automatically mean the sale was worthwhile. Marketplace fees, postage and packaging all reduce what you keep. If you track only sale prices, your business can look healthier than it really is.
The solution is a repeatable calculation for every order. Here is a practical method for Cardmarket sellers, with a worked example in euros and a checklist you can use before buying or listing another card.
Start with the right profit formula
For a simple order-level calculation, use:
Sale profit = card sale proceeds + shipping received − acquisition cost − marketplace fees − postage paid − packaging − other direct costs.
This measures the contribution from an individual sale, not your complete business profit. General overheads and the value of your time still matter. Treat it as a consistent starting point for comparing orders, rather than a complete financial statement.
Calculate your profit step by step
- Record the actual card sale amount. Use what the buyer paid for the cards, after any discount, rather than the original listing price.
- Add shipping money received. Keep this separate from the card price so you can see whether shipping covers your delivery costs.
- Subtract the cards' acquisition cost. Use the cost recorded when you bought them. For a collection or bulk purchase, choose a consistent allocation method instead of treating every later sale as cost-free.
- Subtract the actual marketplace fee. Check your transaction records. For a planned sale, verify the applicable current terms with Cardmarket rather than relying on an old screenshot or remembered percentage.
- Subtract postage and packaging. Include the stamp or label, envelope, sleeve, protection and any other materials used for that order.
- Include other direct costs and check the result. Avoid double-counting a charge already included elsewhere. Record refunds or adjustments against the order if they happen later.
A worked Cardmarket sale example in EUR
Imagine you sell one card for €25.00 and receive €2.00 for shipping. The card originally cost €15.00. For this illustration, assume the transaction's recorded marketplace fee is €1.25, postage costs €1.80 and packaging costs €0.40.
€25.00 + €2.00 − €15.00 − €1.25 − €1.80 − €0.40 = €8.55.
Your sale contributes €8.55 before general overheads and your time. The €1.25 fee is an illustrative input, not a statement of Cardmarket's current rate. Use your actual charge when checking a completed sale.
Notice that receiving €27.00 is not the same as earning €27.00. Equally, subtracting only the €15.00 card cost would produce €12.00 and overstate this order's result by €3.45.
Compare margin without mixing definitions
If you calculate margin against the €25.00 card sale price, €8.55 divided by €25.00 is 34.2%. If you use the €27.00 total received instead, the result is about 31.7%. Neither denominator should be silently swapped between orders.
Choose a definition, label it clearly and use it consistently. For everyday decisions, the euro profit per order is often the easiest number to understand alongside the percentage.
Watch for costs that disappear from memory
Small items are easy to ignore, especially when you process several orders together. Keep a simple record of packaging costs and postage instead of assuming shipping always breaks even. For multi-card orders, calculate the whole order first: shared shipping and packaging should not be charged in full to every card.
Also distinguish cash arriving today from the cost of stock bought earlier. Selling older inventory does not erase its purchase cost. A consistent record makes comparisons between games, orders and buying decisions much more useful.
Check the numbers before your next sale
Use the free Cardmarket and eBay fee and profit calculator to test a sale scenario. Check its fee assumptions and compare estimates with your actual transaction records.
When you need to manage inventory, acquisitions, sales and profit beyond a single calculation, explore TCGPro for Mac. Start with accurate inputs, keep the workflow consistent, and judge each sale by what you keep, not just what the buyer pays.