Looking to buy an AGP card to upgrade an older socket A machine to play some older games on. Specifically, I want one that I can stick my Acccelero S2 on. The ideal card I'm looking for is the Radeon x800/x850 cards.

Are you in the US? If so check this 512mb GDDR3 HD4650 AGP card from TigerDirect for $70. http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=6438898&CatId=3670 It has 1600mhz effective memory it is closer to an HD 4670's 2ghz memory clock vs the reference HD 4650's 1ghz memory clock. After a little OverClocking you should get HD 4670 performance in AGP

If you head over to Anandtech or HardForum you might be able to get an HD 3850 AGP card for $50 - $70 shipped used nd they would be faster than the HD 4650 without OverClocking.

Hey man thanks for replying, but that 4650 looks overkill (in power and price) for what I want to do. I already managed to buy an X850 XT platinum edition off ebay, so I've found my card.