GovDeals.com is possibly the top Government Surplus Auctions in the country and has thousands of auctions going on every day. So why GovDeals? Why not use Ebay? Well items on govdeals.com are usually less than 1/2 the price items on Ebay.com
Whats the catch? Well government agencies both city, state, and county have annual budgets and turn over rates on most products. They then sell in bulk large quantities of computers, printers, office equipment, Equipment, School Supplies, Tanks, Tires, Pipes, Generators, and Construction Equipment and more. There is usually much less competition as far as others wishing to buy these items, and so the prices rarely get overbid.
Give them a try if you are a buyer. http://govdeals.com
Site has been around since 2000.