Your cost basis includes more than just the purchase price. Add buyer's premiums, shipping, grading fees (PSA/BGS/CGC), sales tax paid, insurance, and restoration costs. Every dollar added to basis is a dollar that isn't taxed at the 28% rate.
No receipts? The IRS may assume a $0 basis — meaning you'd owe tax on the entire sale price.
This article contains affiliate links. See our affiliate disclosure.
Every dollar you add to your cost basis is a dollar that doesn't get taxed at the 28% collectibles rate. Most collectors undercount their basis by hundreds or even thousands because they only track the purchase price and forget everything else.
What adds to your basis
- Purchase price (including sales tax at time of purchase)
- Buyer's premium — Heritage, Christie's, Sotheby's typically charge 15–26%. All basis.
- Grading & authentication — PSA, BGS, CGC, NGC, JSA, GIA fees
- Shipping & insurance to get the item to you
- Restoration & conservation
- Import duties & customs fees
Quick example: graded Pokémon card
| Cost | Amount |
|---|---|
| Purchase price (eBay) | $2,800 |
| Sales tax | $231 |
| Shipping + insurance | $18 |
| PSA grading | $150 |
| Shipping to/from PSA | $46 |
| Actual basis | $3,245 |
Sells for $5,000 → gain is $1,755, not $2,200. That's $125 saved at 28%.
Auction house purchases
The buyer's premium is the big one people miss. You bid $25,000 at Heritage, pay a 20% premium ($5,000), plus $380 shipping and $125 insurance. Your basis is $30,505 — not $25,000. That's $1,541 less in tax at 28%.
The box break problem
You pay $200 for a break spot. You pull a card worth $5,000. Your basis is $200 — what you paid, not what the card is worth.
Pull three cards from a $200 spot? Allocate the $200 across all three by relative value.
What does NOT count
Travel to shows, ongoing insurance premiums, storage rental, display cases, club memberships, and your time. (Dealers can deduct some as business expenses — see our dealer vs investor guide.)
Keep your receipts
The IRS can ask you to prove your basis. Save purchase receipts, auction settlements, grading invoices, and shipping confirmations. For trading cards and sports memorabilia, pricing tools like Beckett’s Online Price Guide can help establish current fair market value, which is especially useful when you need to document basis allocations for box breaks. Our record-keeping guide has a full checklist of what to save. If you sell on eBay, StockX, or Whatnot, platform fees reduce your proceeds (not basis) — but track those too, especially as 1099-K reporting thresholds may require you to reconcile your sales. Our calculator lets you input basis additions directly.
When you’re ready to file, our reporting guide shows exactly where cost basis goes on Form 8949.
See how basis changes your tax
Plug in your full cost basis and see the difference it makes.
Open the Calculator →