Depends on game you play and what you run
$260-270 on sale HD 7950 (with Crysis 3 + bioshock Infinite you can sell) / $210-230 HD 7870 Tahiti LE (with Bioshock Infinite + Tomb Raider)
The HD 7850 is expensive now, at $180- 200 or so , a few months back they were going for $170 or so. I guess if you sell Bioshock Infinite code then it'll be $130-150 or so.
The HD 7790 supposedly has a Bioshock Infinite code as well and is supposed to be $150.
edit: if you need to go Nvidia (CUDA apps like Adobe Premiere) , the GTX 670 that competes with the HD7950. Lower, the GTX 650 Ti boost that is going to be released to compete with the HD 7790.
The only GTX 670 you can find for similar prices to the HD7950 is the reference cooled ones, typically PNY or Galaxy (and doesn't come with sellable games).
Edited by AlphaC - 3/23/13 at 7:50pm