I you don't mind going used, then you should be able to pick up a 6600GT for $90 shipped if you look around. I just sold mine for that, and I've seen others listed here for that price as well.
Heck, it's $118 shipped AR at
Newegg. The 6600GT is just a hair faster than the 9800pro in a lot of games and a lot faster in certain games like Doom 3.
Mine worked great over the past year, so it's got my endorsement.