TCG inventory, part 1: cost basis for cards, slabs and sealed

Cost basis is more than the purchase price. Example data.

Every profit number for a card starts with one figure: what the card cost you. That sounds simple until a card goes out for grading, comes back in a slab and sells months later. By then the purchase price is only part of the story.

This series is about keeping a card inventory that tells you what you actually made. The examples use made-up cards and US dollars. The method works the same in any currency.

What cost basis means

Cost basis is the purchase price plus everything you paid to get the item ready to sell.

• For a raw card, that is usually the price plus the shipping you paid to receive it.
• For a graded card, add the grading fee, shipping to the grader and back, insurance and any upcharge.
• For sealed product, it is the box price plus shipping, and storage if you pay for it.

A graded card, step by step

A card bought for $40.00 goes out for grading:

• Purchase price: $40.00.
• Grading fee: $25.00.
• Shipping both ways and insurance: $10.00.

Cost basis: $75.00. The $40.00 is only where it started.

It comes back graded and sells for $95.00. Selling fees and shipping to the buyer come to $12.00.

• Profit with the full cost basis: $95.00 minus $12.00 minus $75.00, which is $8.00.
• Profit if you only count the purchase price: $95.00 minus $12.00 minus $40.00, which is $43.00.

The difference is $35.00 on one card. Across a stack of submissions, that gap decides whether grading paid off at all.

Same sale, two answers. Example data.

Split the grading cost per card

Grading is often paid per submission, with one shipping charge for the whole box. Split it back to each card so every slab carries its own cost.

The example submission has 10 cards:

• Grading fees: 10 cards at $25.00, so $250.00.
• Shipping both ways and insurance for the box: $60.00.

Shipping per card is $60.00 divided by 10, which is $6.00. Each card’s cost basis gets $25.00 plus $6.00, so $31.00 on top of what you paid for it. If one card in the box needed an upcharge, add that to that card only.

Split the box costs back to each card. Example data.

Lots and bulk

Bulk lots are harder. Say you buy a lot of 200 cards for $60.00 and find three cards worth selling on their own. You can split the cost in two ways.

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Equal split: $60.00 divided by 200 is $0.30 per card. Simple, but it makes your three good cards look almost free, and the rest of the lot look expensive.

Split by value: estimate what each part is worth when you buy. In the example, the three good cards look worth about $50.00, $30.00 and $20.00, and the other 197 cards about $50.00 together. That is $150.00 of estimated value for $60.00 paid, so each dollar of value cost $0.40.

• Card 1: $50.00 of value, cost basis $20.00.
• Card 2: $30.00 of value, cost basis $12.00.
• Card 3: $20.00 of value, cost basis $8.00.
• The other 197 cards: $50.00 of value, cost basis $20.00 together.

Split by value, $0.40 of cost per $1.00 of value. Example data.

The value split gives profit numbers that look like what really happened. Whichever method you choose, use the same one every time.

Sealed product

Sealed boxes follow the same rule. A box bought for $120.00 with $9.00 shipping has a cost basis of $129.00.

If you open it, the $129.00 moves to the cards you pulled. Use the value split from above. If you keep it sealed, the full $129.00 stays on the box until it sells.

Sold cards

When a card sells, record the sale price, the fees and shipping on that sale, and the date. Profit is the sale price minus fees minus cost basis. Then mark the card as sold so it drops out of your collection value.

That last step is easy to forget, and it causes the most common error in card spreadsheets: a sold slab still counted in the portfolio value months later.

A short routine

When you buy:

1. Log the purchase price and shipping per card, or the lot price with your value split.

When you submit for grading:

1. Add the grading fee and your share of shipping and insurance to each card.

When you sell:

1. Log the sale, the fees and the profit, and mark the card as sold.

What comes next

Part 2 looks at the grading decision itself: how to compare the expected graded value after fees against the full cost to grade and the raw price today.

If you want this in one place, our TCG Vault workbook tracks raw cards, graded slabs and sealed product with cost basis including grading, logs grading submissions and sales after fees, and shows profit, loss and ROI per game and per slab. It works in Excel or Google Sheets.

https://sizerunstudio.gumroad.com/l/tcg-vault?utm_source=medium&utm_medium=article&utm_campaign=tcg-md_inv1

Example data with made-up cards. Not affiliated with any card game or grading company. This is not tax advice.