Here are some great tips to help make sure you are getting what you paid for when purchasing sports Memorabilia new, signed or game used signed

1) Ask the seller how they came across the item

2) Do they offer an Authentication service prior to shipment or is the item already authenticated? (example PSA DNA, PSA Quick Opinion)

3) Is thier auction Insured by any Known third party and verifiable? (BuySafe, PayPal..etc)

If they answer question 1 and answer or you can see clearly in the auction answers to 2 and 3, then you can be pretty comfortable that the seller is selling an authentic item or at least that you are 100% protected. The best guarantee to protect you from any potentially fraudulent seller is to only pay with Credit Card directly,  through paypal or through any service that you are able to file chargebacks through your Credit Card issuer. I have been buying and selling on eBay for almost 10 years.