what you could do is print out a list of everything R5 and above for the systems listed, bring the list with you when you go to check out the games, then check and see if any of them are on that list. I've actually put the DP rarity guides onto my PSP for when I go lookin' for rare stuff. Its helped out quite a bit. You may also want to check ebays completed listings on certain titles to see how much they've sold for in the past few weeks. Usualy if there are no copies to be had on e-bay, buy it. As far as atari goes....look for Swordquest: Waterworld (not earth or fireworld), Texas chainsaw massacre, Chase the Chuckwagon, and whatever the guide says is an R7+