: Auctions can land you a deal, but "Buy It Now" options allow you to secure a specific price immediately if you’re worried about being outbid at the last second.

: While a blurry photo might hide a bargain from a casual seller, professional sellers with thousands of feedback points who use blurry images should be treated with extreme caution—they may be hiding flaws.

: Aim for sellers with a 99% positive feedback rating or better.

: If a seller doesn’t offer returns, you generally have 3 calendar days after delivery to request a return if the item isn't as described.

: Raw (un-graded) coins are often listed as a higher grade than they actually are. A good rule of thumb is to assume a raw coin is at least one grade lower than advertised.