You can save a bundle by buying a used digital SLR on Ebay but there are some things you need to watch out for. Most sellers offer only a 7 day return policy if even that. Read their warranty policy closely.

Of course the most important thing you want is a camera that is in good working condition but also you need one that suits your needs.

Are you looking for a semi pro model to use commercially? If so stick with the higher end models of common cameras such as Canon and Nikon. You will find more lenses that are compatable than with newer digital SLR cameras such as Sony.

There is a lot of confusion about the number of megapixels. A Canon 30D, while only having 8.2 megapixels may take just as good of photos as a 40D that costs twice as much with 10.2 megapixels. If you are not blowing the image up to wall sized you will not notice and can save a bundle.

Ask the seller questions, such as how often the camera was used and for what purpose. Cameras used in a business by everyone on staff may not have been as well taken care of as one that was used personlally in a home. Ask if it was kept in a case, if there are any scratches, large or small on the lens and if it has ever been serviced.

Older SLR's often do not have automatic sensor cleaning and may need to be serviced to clean the sensor or "digital film" that receives the image.

Ask for many close up pictures and if all of the buttons are operable.

It is important that the camera come with all download cables and software. While drivers and software can be had for free on most manufacturers sites, things like download and video adapter cables can be pricey if bought from the factory and it can take weeks to get them. You want a package that includes all accessories, manuals, etc and does not require you to order any missing items.

Ask if the camera has ever been dropped. While you may or may not get an honest answer, avoid any camera that has suffered a drop since it may work buy have hidden problems about to go wrong.