Except for video, there really isn’t an advantage to spending more. I’m using a cheap A10 AMD APU 8G RAM desktop and my bottleneck in gaming is my 6770 video. My i7 16G work machine isn’t much faster.
The Video Card will almost always be the bottleneck now since that's where most of the processing power has moved to.
Both my son's have AMD FX-8320's that I picked up for $99 each, 8GB of 1866 memory, 250Gb SSD's and GEForce GTX 660 SuperClocked video cards and they get easily 100+ FPS on Max/Ultra settings on damn' near every one of their war games. (Don't ask me which, I have no idea what games they're into. I just look at the FPS.)