Well you aren't exactly in the right part of the forum for this, but I can give you a rough idea what to look for. For more help you should try posting in the "Systems" section, as that section is pretty much picking out entire builds with parts and not much of anything else. Also you will need to mention if you have keyboard, mouse, or a display because if you don't and need those also your price will jump greatly.
If you do have the display, you should be looking to spend about this much on each part:
Power Supply: Corsair $35-45
DVD Drive: Any brand $15-20
PC Case: $40
HDD: $50
Keyboard and mouse: $20
RAM: 2x4GB $60
Motherboard: $60
CPU: Intel i3 $120
GPU: AMD R7 265 or R7 260x $120
If you don't have a display it would be this instead:
Power Supply: Corsair $35-45
DVD Drive: Any brand $15-20
PC Case: $40
HDD: $50
Keyboard and mouse: $20
RAM: 2x4GB $60
CPU: AMD A10-7850K $170
Motherboard: AMD FM2+ $60
CPU Cooler: $15
Then the rest on a monitor.