Save your money, your only option with this much money would be to find used server parts. This would give you a server board, xenon quad core, 8gb of ram, a PSU, and a very cheap case for $150. Even after that you still need a graphics card and if you expect to play the latest titles you need at least a 750ti, or 950 which is $100-$150.
So now, let's say you manage to get together all these parts, they all work properly and the system runs. You still have a "gaming" pc that runs on server parts which are not designed for gaming and that developers do no intend to run said games.
Long story short, wait and save more money.