Well for something the same price as the 7850k, you can get the Athlon 750k CPU paired with an HD 7770 GPU which will give you much better performance.
Depends on your resolution. Low settings at 30+ fps if at 1080p, medium settings at 30+ fps at 720p. CoD Ghosts is horribly optimized though, so you'll see some frame rate drops.
Something along the lines of the AMD HD 7750 or 7770 would be good, and a lot better performing. You can pair either of those with the Athlon 750k CPU and pay the same total price or even save a little.