Posted By:
davidcyclebackA buyer either knows or doesn't know that a card or autograph or poster is genuine. I'd never advise a collector to spend $10,000 on an item that he doesn't know is authentic. If a collector regularly spends that kind of dough on memorabilia he doesn't know is authentic, he's going to get burned sometime.
In making a decision, a collector often pools his knowledge and experience with the opinions of others (SGC, PSA, REA, others), which is a good approach. A collector should neither entirely rely on nor eschew expert opinions.