I have a i5-2400 & 8GB RAM. I had a GTX260 core 216 896MB ram and away from buildings I would get 50+FPS on medium @ 1680x1050.
I upgraded to a GTX 660 and was able to kick everything up to high. It is rare that I drop below 35 fps from what I have noticed. I am pretty steady from 45-60 FPS, although I have adaptive Vsync on so it won't go above 60.
It seems it has already dropped $15 in the past week. I spent $229 on it from newegg, but compusa and tigerdirect have it cheaper now.
http://pcpartpicker.com/part/evga-vi...rd-02gp42662kr