With the price of gold going up your old pcs are finally worth something.  Don't throw them out!
Check this out.
http://www.ebay.com/itm/25-pounds-Scrap-computer-Motherboards-Gold-Recovery-/250940119131?pt=LH_DefaultDomain_0&hash=item3a6d32585b
http://www.ebay.com/itm/Scrap-Gold-Computers-/220901756462?pt=LH_DefaultDomain_0&hash=item336ec54e2e
http://www.ebay.com/itm/40-Gold-Fingers-Computer-Boards-scrap-recovery-/150708308929?pt=LH_DefaultDomain_0&hash=item2316ea4bc1

Info on gold in computers
http://www.scrapmetaljunkie.com/244/computer-gold-fingers-2

It seems the older stuff from the 70s & 80s are worth more.
I kept all my old pcs and ones people have thrown out.  I got over 20 complete systems.
Gonna take them apart and ebay them!

Just more money for wrenches :)
Skylab

You have room to store and disassemble computers?  you need more tools   bob w.

In 2005 when I retired from the University of Alabama in Huntsville, we were dismantling old computers and testing the boards.  All good boards were kept for repair parts, but all bad boards were recycled for gold.