I'm building it for a friend, the 600 would include computer, monitor, keyboard, and mouse. All it needs to do is run minecraft at high settings at around 45 fps.
Trying to build a pc for less than $600
Guest
Hardware: FX-6300, GTX 750 or Radeon HD 7790, 8gb RAM, half a tb HD, ASRock 960GM/U3S3 FX motherboard?
You can get keyboard/mouse bundles from decent brands like logitech for $7, BitFenix Comrade is the cheapest decent case I've ever come across ($45).
It's hard to build a PC on that budget but I hope this helps.
Nachoborn
http://pcpartpicker.com/parts/partlist/
The King Possum