Trying to build a gaming PC under $500

This build won't work. The motherboard you have chosen only supports up to 95W CPUs. You are better off going with this board

ASRock 960GM

as it supports 125W CPUs and will allow you to use AM3+ CPUs latter on. As for high/Very high you won't hit that with more demanding games using that video card, but might be able to on older or less demanding games.