:DIt is a good deal. I think you can go for 8800 GTS. You will get better performance with it. XFX GeForce 8800 GTS is clearly the winner for games and synthetic benchmarks. The best of all is the fact that 320 MB almost never limits your game play. The only case where 320MB card loses from 640 MB one was FEAR with high resolutions. If you use 1280x1024 or similar resolutions this is nothng to worry about. If you want to go over 1600x1200 you should consider 640MB card. Right now the price for XFX Geforce 8800 GTS is pretty low. A recent deal is only $256 instead of $300. Here is the link to the deal I found.
http://dealstudio.com/viewtopic.php?t=29625
Hope this helps.