As a general rule, I limit my purchases to marketplace sellers that are fulfilled by amazon. Through this frame of logic, I recently stumbled upon pieceofmindmedia and have bought quite a few "like new" games from them.
Out of 11 purchases I have had very few but heart-breaking problems. The 1st one was with Thousand Arms for the PS1, listed like new but missing all of the bonus content. Forgiveable, because of the price and the great condition in which everything else arrived. The 2nd one was with Alundra for the PS1 which, even thought it was listed like new, arrived with quite a few scratches on the case. I let it pass, because everything else was like new. Then Grandia arrived, and that's when the proverbial shit hitted the fan. The case, the 1st disc and the manual looked fantastic. But instead of the 2nd disc, they sent Gauntlet Legends for the Dreamcast. OMGWTF! I didn't made an scandal out of it, because Amazon refunded my purchase as swift as the wrath of god. I was very dissapointed with Pieceofmindmedia...but forgave them when I saw them selling Valkyrie Profile for the Ps1, Tactics Ogre for the ps1, Bangai-O for the Dreamcast, both Etriand Odysseys and Secret of Mana for the Snes.
After reading this thread, I'm a little worried that they may mix up my orders or my games, yet again, but feel relieved to know that Amazon has my back if anything wrong happens. Stil, I wish I could have found this thread around the time pieceofmindmedia sent me Rez for the PS2 "shrinkwrapped". That game felt resealed, even thought everything about it look and felt like new. Including the inner ring of the disc.