PCPartPicker part list:
http://pcpartpicker.com/p/LCTZ
Price breakdown by merchant: http://pcpartpicker.com/p/LCTZ/by_merchant/
Benchmarks: http://pcpartpicker.com/p/LCTZ/benchmarks/
CPU: Intel Core i5-3350P 3.1GHz Quad-Core Processor ($164.99 @ Newegg)
Motherboard: ASRock Z77 Pro4 ATX LGA1155 Motherboard ($104.98 @ Outlet PC)
Memory: Kingston HyperX Blu 8GB (2 x 4GB) DDR3-1333 Memory ($46.99 @ Microcenter)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($69.98 @ Outlet PC)
Video Card: Sapphire Radeon HD 7870 XT 2GB Video Card ($234.99 @ Newegg)
Wireless Network Adapter: Rosewill RNWD-N1502UBE 802.11b/g/n USB 2.0 Wi-Fi Adapter ($9.99 @ Newegg)
Power Supply: XFX 550W 80 PLUS Bronze Certified ATX12V / EPS12V Power Supply ($54.99 @ Newegg)
Optical Drive: Samsung SH-224BB DVD/CD Writer ($15.98 @ Outlet PC)
Operating System: Microsoft Windows 7 Home Premium SP1 (OEM) (64-bit) ($89.98 @ Outlet PC)
Total: $792.87
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-03-23 10:38 EDT-0400)
A bit above the budget, but its the best right now.