Budget gaming PC help

[Ankur]

Need help picking up parts from newegg please the budget of my customer is only 500$ and they want it for mostly gaming and college.
They just need the tower and no OS.
Please suggest me parts as I have never built such a small budget PC.

 

[daisymtc]

$510 after MIR, price from newegg as usual
AMD Athlon II X3 450
ASUS M5A78L-M LX AM3+
G.SKILL 2 x 2GB DDR3 1333 F3-10600CL9D-4GBPK
SAPPHIRE 100282XTREME Radeon HD 5850 Xtreme 1GB (or just get 5770 to stay absolute under $500)
Seagate Barracuda 7200.12 ST3500418AS 500GB (or faster SAMSUNG Spinpoint F4 HD322GJ/U)
LG DVD Burner Black SATA Model GH24NS70 - OEM
Rosewill CHALLENGER or NZXT M59 (with MIR $10) or Thermaltake V3 ($45, $5 off promotion, $10 MIR)
XFX Core Edition PRO550W (Or get CX600 to make it $500 after MIR?)