How do I calculate profit margin on Pokémon card sales?

The actual formula

Profit = Revenue − purchase cost − marketplace fee − payment fee − packaging − share of monthly fixed costs. Then Profit Margin = Profit / Revenue. The trick is being honest about every line. Most sellers forget the fixed costs and overestimate their margin by 10-15 percentage points.

A worked example from my actual sales

A $26 sale at 130% markup of the Cardmarket market value:

• Card market value: $20 (you sold at $26 = 130% markup)
• Purchase cost: ~$14 (I aim for 70% of market value when buying bulk; up to 75-80% for very strong collections)
• Platform fee at 10%: $2.60
• Payment fee: ~3% = $0.78
• Packaging (envelope, sleeve, top loader): ~$0.50
• Variable cost subtotal: $17.88
• Revenue minus variable cost: $8.12 (~31% margin before fixed cost)

The fixed costs everyone forgets

Fixed monthly costs are not optional and they kill your margin if you ignore them. My current fixed stack: Shopify subscription (~$30), TCGPowerTools (~$50), postal address (required for business compliance in Switzerland), domain and email tools. Total around $100-150/month before any cards are sold.

If you sell 100 cards a month, fixed cost is $1-1.50 per sale. If you sell 500, it is $0.20-0.30. Volume directly improves margin by amortizing these costs. This is also why ramping up listing volume matters so much in the first months — the fixed cost stays the same, but each new sale pays a smaller share of it.

The buy-price discipline

The single biggest lever on your margin is the purchase price. I aim for around 70% of market value on bulk; for very strong collections with many illustration rares I go up to 75-80%, but anything above 80% is risky because you lose your safety margin against damaged cards, lost shipments, and price drops during the holding period.

Always factor in a safety net: cards get lost in transit, some arrive damaged, and you cannot sell every card you bought. If you ignore this you will look at your profit per sale and miss that 5-10% of your inventory disappeared into the void.

Different markups per card value

I do not use a flat 130% markup across the board. Lower-value cards (under $5) can carry a higher markup because the buyer is not deeply price-comparing. High-value cards (above $50) need a tighter markup, often 110-115%, because buyers do compare Cardmarket Trend across multiple sellers and won't click on the highest one. Tune your markup by card-value bucket and your sell-through rate will improve.