I've bought countless things on ebay. As long as your semi-carefull, you'll be able to find some great deals. For a small extra fee you can also buy through escrow, check out your product for a period of time and if its satisfactory the money is put through. Ebay does provide ways of getting your money back for products that are different than described as well.

Also, if you're unsure of buying from a particular seller, look at their rating and read their feedback, it'll give you a good idea of how well they do business.