(very) cheap build

[Rray]

An I3 paired with the cheapest board and a 6850 should be enough for your friend. AFAIK, it won't put your friend past his budget. Besides, i3 is more than enough for gaming if paired with a 6850 or a higher GPU. Though, if you really want to save some money, you could go with a 4850. If you could find a 500w FSP Supersonic in your area, that would be good as well since it is one of the cheapest 500w PSUs around. Using a 380W PSU with a 6850 would be cutting it close.

 

Also, the APU idea is good enough. If you plan on using a 380W PSU, the 6670 and the A8 should be enough to play most games at high settings since the 6670 does not really consume a lot of power. Plus, at load, it could barely hit 300W. At least, that is what I know. Also, the performance should be on par or better than a 6790 and a few FPS below the 6850.