As a reasonably new buyer on Ebay, I thought I'd share a few thing you might want to consider before buying. Check out all sellers who are offering the item you want. Don't just pick the cheapest one, read the description, payment advice & returns policy to make sure you are happy with all conditions before you bid or buy. Take the time to read feedback, find out if negetive feedback is justified (sometimes it sounds like very fussy buyers who didnt read the description properly) On the other hand, if several people are complaining about the same thing (eg slow service), you might want to avoid them. The advantage of feedback is that most sellers (especially shops) value positive feedback & will do what they can to rectify any problems. The biggest thing I discovered is the varied quotes of postage. If an item is considerably cheaper from one seller, compare the postage. I sometimes find the total cost from such sellers turns out to be dearer because they have increased the postage by the same amount as they have discounted the price. Also, I have come across a relisted item supposedly discounted to get rid of it, but again, the postage has been increased. Finally, if you are after more than one of something, say dvd's, then it may work out cheaper to purchase them all from the same seller & receive a discounted postage than buying off different dealers where the initial cost is cheaper, only to find that when the postage is added up, it works out more expensive.
I have had nothing but positive experiences buying on Ebay. I think if you research carefully, most people will find the same!