Core setup for up to 6 graphics cards, a nice inexpensive expansion option for any mining farm.

Qty (3) MSi 870-G45 motherboard (just the motherboard + i/o plate for a case)
Qty (3) AMD Sempron 140 CPU (OEM w/fan + heat sink)
Qty (3) 2GB DDR3 RAM
Qty (1) 1GB USB stick
Qty (2) 4GB USB Stick

Just add a power supply + GPUs and you are ready to mine.

$350 (or BTC equivalent) including shipping from the Seattle area, I will guarantee against DOA and promptly refund any returned component.