For starters, I had a budget of $100 a month, strictly enforced by my wife. The SSD was a Christmas present, so I don't count that towards the overall cost (though it is nice). I purchased the components over the course of about 6 months, watching for sales and cashing in my coin jar twice to stretch my buck as far as I could.
Pretty decent build, and no you don't need to buy an i5 blah blah. Heres the "dirty little secret" about all the gaming FPS reviews:
For playing games your CPU will have the same framerate. (Since a 60hz monitor=60 frames per second, it doesn't matter that i5 gives you 90FPS in a game and an FX-6100 only gives you 65 or 70 or whatever. Your computer could be sending 1000 frames per second to the monitor, you're only gonna see 60.