He is correct! I just bought a signed 1st/1st Talisman on Ebay from a seller with 100% positive feedback, but the signature appears to be fake. The seller says they just "consign" them so they will issue a refund (which means they will just sell it to someone else who won't call them out). Super frustrating, but that's part of the fun of the hunt for neat collector items.
Good luck and "safe" searching!