I just bought my Minolta Dimage 7hi online at ebay. Know your prices well, check the feedback file on the sender, make sure they offer the appropriate warranty for your camera and the hope for the best. Also you must factor in shipping and handling. You are also better off using a credit card so if you do run into problems they may provide help. Or using a vendor through dpchallnge or cnet they rate the online vendors.
Good luck
A vendor is the person or business who is selling the product.
I also bought my (2) digital cameras at ebay. I agree with everything that margem said. In addition, if you can establish e-mail or phone contact with the seller "before" you bid (for example, to ask any questions you have), you can get an indication of how responsive the seller will be for completing the sale. I also researched the seller by looking them up in the phone book or visiting their online shopping site (if the seller has one) to verify that the seller is a legitimate business.
I preferred to pay the seller directly, over the phone with credit card, rather than pay through the ebay payment options. You can ask the seller if he/she will do this before you bid.
Both of my ebay purchases were very positive experiences, and I saved about $200 CDN each off the retail price (which was, unfortunately, offset by shipping charges).
if you are going to buy from an online company, check out
Resellerratings.com, they have customer reviews of nearly any online company out there. People leave reviews of their buying experiences, and leave invaluable information about the seller's policies and procedures.