Come on, Jess, you know that I get burnt on Ebay as much as anyone.
I search several hotel names like hyatt, sheraton, wyndham, marriott, etc. Then open all catagories and hone in on "Travel" and "Gift Certificate". Generally if the deal seems too good to be true, it is! However, there are quite a few times when people do not think about an expiration date on a certificate until its too late and they can't use them. They end up posting them for peanuts. I got a room at Hojo's on 192 once for $10.
You need to read carefully and avoid timeshares.