Here's what I recommend :
PCPartPicker part list:
http://pcpartpicker.com/p/2RMCj
Price breakdown by merchant: http://pcpartpicker.com/p/2RMCj/by_merchant/
Benchmarks: http://pcpartpicker.com/p/2RMCj/benchmarks/
CPU: AMD Athlon X4 760K 3.8GHz Quad-Core Processor ($81.99 @ Newegg)
Motherboard: MSI FM2-A75MA-E35 Micro ATX FM2 Motherboard ($57.78 @ Newegg)
Memory: A-Data XPG V2 8GB (2 x 4GB) DDR3-1600 Memory ($69.99 @ Newegg)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($59.98 @ OutletPC)
Case: Silverstone PS08B (Black) MicroATX Mid Tower Case ($39.99 @ Amazon)
Power Supply: Rosewill Hive 650W 80+ Bronze Certified Semi-Modular ATX Power Supply ($49.99 @ Newegg)
Total: $359.72
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2014-02-12 00:35 EST-0500)