You could cut corners even more and get on-board video. Depends if he plans on doing any gaming, but seeing as you only have $300, it doesn't seem so. Nvidia just released (or plans to release) a new line of on-board video N-force or something like that.
This is what I have in mind for mobo:
http://www.newegg.com/app/ViewProduc...138-234&depa=1
Saves you $70 bucks to cut out the video card, and it has on-board LAN and on-board 6-channel audio.
My choice for case/PS:
http://www.newegg.com/app/ViewProduc...192-008&depa=1