Ever so slightly over-budget without MIR, if it really did need to be under $650, just swap the i3-2120 for the i3-2100. Other than that, looks great
EDIT: Also, shop around for HDD offers. Prices are high inflated currently but good offers do keep regularly popping up. If you don't need much storage space there's some good offers going round on 320GB HDD's. Try to grab something that's 7200RPM though like the one suggested above.