Find a local source

When you buy your used computers locally, you're in a better position to test them and, if necessary, return them. For that comfort level, you may pay more than you would online.

I recommend: Look in your local Yellow Pages under "Computer & Equipment Dealers, Used & Recycled." Other good sources include local classified ads and periodic computer expos when they come to town; search Local.com for "computer expo" (include the quotes) in your city.

Shop online

Not surprisingly, you'll find the widest array of used computer options online, not simply from sellers, but also from auction sites, recyclers and liquidators. As a rule, the lower the price, the more cautious you must be about the supplier.

I recommend: For computer auctions, check out Liquidation.com (especially for quantity lots), Yahoo! Auctions and eBay. Try also Intechra Outlet, which offers a range of brands.

Look for refurbished PCs, overstocks and discontinued models

Major PC manufacturers take their defective returns and former leases, repair them to factory specs and resell them, often from their Web sites. They guarantee that the PCs are as good as new but within a dramatically shortened warranty period. They also may sell off discontinued models at a discount, until they run out. Third-party refurbishing/overstock resellers do the same thing the manufacturers do, minus the assurance you may feel from buying from the original maker.

I recommend: Check out the manufacturer outlet sites for Dell, Gateway and HP. For a third-party option, check out used computer dealers who have eBay stores. NexTag offers direct access to deals from a variety of vendors along with ratings of the PCs themselves.

Make sure it's a good deal

How do you know that the price on a used computer is a good one for a computer of that age and specs?

I recommend: Check the blue-book value of a computer you're considering on Orion Blue Book. Using any Web search engine, use the computer's model name or number to find the same computer for sale elsewhere and compare prices (don't forget to factor the warranty and shipping costs into your comparison).