Is it worth buying trading cards secondhand?

Yes, if you can trust the card. Fakes are common for famous cards, and the grade drives the price. Graded cards and eBay's Authenticity Guarantee remove most of the risk.

Check before you pay

Tick them off as you go:

Graded card: type the certification number from the label into the grader's own website (for PSA: psacard.com/cert) and compare the card, the grade and the photos.
Ungraded card: ask for clear photos of the front, the back and the corners.
On eBay US, single trading cards of $200 or more go through eBay's Authenticity Guarantee: the card is checked before it ships to you. Look for the badge on the listing.
Pokemon cards: compare the font, the colors and the back with a card you know is real; fakes often look too glossy or use the wrong font.

Red flags

"Reprint", "proxy" or "custom" in the title.
Sealed packs or boxes from a seller without history: resealed packs exist.
A graded case with no certification number, or a label that does not match the grader's website.

Which ones still make sense

Graded cards (PSA, BGS, CGC) for anything valuable.
Ungraded cards for collecting and play.
Mystery packs and repacks: a lottery, not an investment.

Live listings on eBay

A few current listings, United States. Asking prices; read each listing's condition and returns.

Sources: PSA certification lookup (psacard.com/cert); eBay Authenticity Guarantee for trading cards, $200 threshold reported by Sports Illustrated, July 31, 2026.