Here is something that might be interesting for MJ users:

http://shop2.frys.com/product/559502...H:MAIN_RSLT_PG

This machine will still need memory, an HDD and a CPU, but you should be able to get the entire rig setup for under $150. It is small, quiet and the perfect kind of machine for a MJ server. Of course, at the same time you could turn it into a nice NAS