Which PSU for this build

So this is the list for a PC i want to build because i am selling my current build to a friend. I dont know much about PSU's so please help me pick a PSU that can power the build but isnt overkill, fairy priced and modular. 

Build: http://pcpartpicker.com/p/2OGxH


50 bucks 80+ gold rated, semi modular (4+4pin + 20+4pin perma-attached but you need those anyway right?)