I'd make a few adjustments, personally.
I would use the same HDD, PSU, Heatsink and Memory listed, but change a few other things.
I'd swap to This
Case, which is $25 plus free shipping, so a $20 savings.
I would go with a Phenom II X3
as a processor. The addition of L3 cache trumps the extra core in most basic apps and gaming, IMO. Plus, you have a good shot at getting that 4th core for free.This is a smoking deal
on a GT240 which isn't quite as good as the card above, but will play games at 17" CRT resolutions great, and it'll save another $30.
And finally, to trim a few more bucks you could pick up This Asus
motherboard, which isn't as nice as the one 002 reccomended, but it does the job and is only $49.
That total comes to $527 with $80 in MIR, so $447. If you want to spend the extra $50, you could consider something like a GTS 450
, which would put you just about $10 over budget.