I heard a good one the other day - a guy was looking for a Rolex watch. He got caught up in bidding on Ebay, and when all was said and done, he'd paid $3000 FOR AN EMPTY ROLEX BOX!!! It called it out right in the auction, but this fool ( as well as at least one other), didn't read the fine print. I bet that seller laughed all the way to the bank...
Ebay, just like any forum with a lot of independent sellers (antique shows, home shows, county fairs, etc), is based on the premise of buyer beware. If you're careful, and you check the seller out before you bid, you shouldn't be disappointed. And, when you receive your merchandise, if you didn't get what you thought you paid for, most sellers will refund your money. Now both PayPal and Ebay offer buyer satisfaction protection as well.
Most of the sellers I've worked with in the past 4.5 years have been very above board and honest, and have bent over backwards to make sure I'm happy.
Of course, there are some that give the whole system a bad name. I dealt with one recently who charged an OUTRAGEOUS price for shipping "and handling", and refused to negotiate. My husband sells full time on ebay, and goes the extra mile and more to help his buyers save as much money as possible on shipping.
Now - it WAS my fault that I didn't read the 2 point fine print in the auction I bid on, so I paid the ridiculous handling fee. BUT - I also left feedback appropriate to the transaction.