Slight tweak on the above build to bring it under budget, think the PSU is probably better quality too:
PCPartPicker part list:
http://pcpartpicker.com/p/BqMjMp
Price breakdown by merchant: http://pcpartpicker.com/p/BqMjMp/by_merchant/
CPU: AMD Athlon X4 860K 3.7GHz Quad-Core Processor ($69.99 @ NCIX US)
Motherboard: ASRock FM2A88M PRO3+ Micro ATX FM2+ Motherboard ($56.99 @ Amazon)
Memory: Kingston 8GB (2 x 4GB) DDR3-1600 Memory ($38.99 @ SuperBiiz)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($46.89 @ OutletPC)
Case: Silverstone PS08B (Black) MicroATX Mid Tower Case ($34.99 @ Amazon)
Power Supply: Antec EarthWatts Green 380W 80+ Bronze Certified ATX Power Supply ($38.99 @ SuperBiiz)
Total: $286.84...