PCPartPicker part list:
http://pcpartpicker.com/p/Vvk823
Price breakdown by merchant: http://pcpartpicker.com/p/Vvk823/by_merchant/
CPU: Intel Pentium G3258 3.2GHz Dual-Core Processor ($64.89 @ OutletPC)
Motherboard: ECS B85H3-M9 (1.0) Micro ATX LGA1150 Motherboard ($36.99 @ Amazon)
Memory: Corsair Vengeance 8GB (2 x 4GB) DDR3-1600 Memory ($46.99 @ Newegg)
Storage: Seagate Barracuda 250GB 3.5" 7200RPM Internal Hard Drive ($24.45 @ Amazon)
Video Card: MSI GeForce GTX 750 1GB Video Card ($64.99 @ Newegg)
Case: Xion XON-310_BK MicroATX Mid Tower Case ($23.98 @ Newegg)
Power Supply: Antec EarthWatts Green 380W 80+ Bronze Certified ATX Power Supply ($27.98 @ Newegg)
Total: $290.27
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-07-07 14:03 EDT-0400
You cant build a PC with an i5 for 250$
this does not include the OS so you will have to get that from somewhere or run linux.