The real bottleneck here is the gpu. I own a 7770 and can barley play BF3 on ultra at 30fps. In all honesty a 7750 has no place in an $800 gaming system.
I agree with incognito, you are as dumb as a log and I doubt you have any real experience with computers if you think a 7750 is overkill.
A 7750 would pair up nicely with a phenom dual @3.6ghz and 4gb ram in a budget rig.