Which leaves a fairly dismal amount of $79 for the GPU. No doubt you could scrounge around for cheaper parts and make another $20 or so, but this already the lowest you can go without compromising too much.
I wouldn't expect much performance out of the GPU.
The build has the advantage of being easily upgraded, the biggest performance boost would be from a better graphics card, and then upgrading to a Bulldozer CPU. Then you would have a respectable gaming rig.