I had 2 x 9600's GTX's some years ago. Good cards, but hot hot hot.
A friend of mine mentioned they are playing BF3 on their old 9800(s?).
Agreeing with everyone of course, your settings will be as low as possible and your resolution will probably be in the toilet.
I'm not sure getting a graphics card that old will be worth the FPS headaches and/or other graphics issues you may come across.
Agree with Wolfram though - I got the 560 and it wasn't terribly priced. Even a lower end 500 series or high end 400 series would probably do alright. At the very least you'd run at low settings but decent resolution - and that's key.