Hey man if you want to raid mythic and have high fps you need a HIGH END CPU processor, looking at your budget i would spend atleast $175 on a CPU all you really need for a raiding pc is.
motherboard
psu
cpu
gfx card
hard drive
case
I f you already have some of these then i would suggest dumping all your money on CPU + Motherboard/graphics card. But the most important thing is the processor man i cannot stress this enough