Just remember this is a budget build for a reason. There are many places this could be improved, just not for this money. For games like Dota, Heroes, and Diablo 3, you should not have any problem at high settings, but you may find that ultra settings might not perfect. They'll look way better than your integrated graphics, but just about anything will. I think you'll find that you will be able to play all but the newest and most CPU hungry games on medium to high settings at 1080 with this setup.
That does remind me, did you need a monitor? I completely forgot about that and if you needed one, that's going to put you way over $400...
Also if you need a new copy of Windows it'll run you about $90.
Also your case only comes with one fan. I would recommend at least one more to get some more airflow:
NewEgg case fan
It's also a blue LED fan, so it will match the fan that comes with your case.