If you're looking for a good video card for a cheaper price, get the ATI Radeon HD 4830 512mb from Sapphire. It's the equivalent of a 9800GT 512MB. Also, the game isn't THAT cpu hungry, I run it maxed at 1280x1024 and most maps run fine with 10-15 players. This is entirely because of the cpu being so crappy, the video card should handle the game no problems. In most games I run 24x AA just fine with all the graphic settings turned to max, such as FEAR or WoW, UT3 hates Anti-aliasing in my experience.
I have an AMD Athlon 64 3700+ 2.2GHz 1MB L2, that I bought somewhere between 2004-2007. Meh I forget when I build this hunk of crap, but the only thing that hasn't been changed is the mobo/cpu.
Someone please buy me a new combo .
PS: For the record, I am actually using the Radeon HD 4830 from Sapphire, and it is extremely stable with plenty of power. I bought it for $90 on newegg.com