Are you looking to setup a miner? I have an extra used mainboard setup that I will sell for 20 bitcoin
for a bundled package. Just add a storage device, PSU and four video cards of your choosing to begin mining. This setup was proven stable and turning out 1.26GH/s with four little 5830s when I took it offline.
Free shipping within US.
1. Biostar A870U3 Mainboard
(manufacturer's specs: http://www.biostar-usa.com/app/en-us/mb/introduction.php?S_ID=524
2. AMD Sempron 140 CPU
3. 1GB DDR3 1333 RAM module
4. 4 x PCI-E Risers (un-powered)