PCPartPicker part list:
http://pcpartpicker.com/p/QQ8BJx
Price breakdown by merchant: http://pcpartpicker.com/p/QQ8BJx/by_merchant/
CPU: Intel Core i3-3220 3.3GHz Dual-Core Processor ($109.99 @ SuperBiiz)
Motherboard: Gigabyte GA-H61N-USB3 Mini ITX LGA1155 Motherboard ($59.99 @ Mac Mall)
Memory: Corsair Vengeance 8GB (2 x 4GB) DDR3-1600 Memory ($66.98 @ Newegg)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($47.99 @ NCIX US)
Video Card: Gigabyte GeForce GTX 750 1GB Video Card ($99.99 @ Micro Center)
Case: BitFenix Prodigy (White) Mini ITX Tower Case ($77.99 @ SuperBiiz)
Power Supply: Corsair Builder 430W 80+ Bronze Certified ATX Power Supply ($34.99 @ Micro Center)
Total: $497.92
Prices include shipping, taxes, and discounts when available