Generally ebay is a cool place, though here in the UK a lot of stuff is cheaper on play than it is on ebay 2nd hand! I've only been ripped off once on ebay and that was only for something small.

However, a mate of mine wanted to get a DVD writer, he knew he could get the standard model of the one he wanted in Manchester for about £80, but he found the advanced one on ebay, for which he bidded on and paid £105 for it when he won the auction. However, when it arrived in the post, it was not the one the seller had advertised, it was the bog standard one that my friend could have bought for 80 quid! He has complained to ebay, but the seller just came back with some bullshit that isn't even relevant to the situation, and so far ebay have done fuck all in trying to help my friend (who isn't exactly in the money) to get his money back or to punish the seller.

Be careful with who you deal with! Personally I wouldn't buy anything really big off there, just anime DVDs etc that are such a rip off in the shops (*cough* HELLSING *cough*) that you don't have much choice, or manga (if you look hard you can find some well ace stuff - I got 40 old manga comics containing Appleseed, shitloads of others and the entire story of Akira for like £7.

So in short, 99% of the time you will get a fair seller, theres just a few who are total twats...

EDIT - *wonders why the pound sign shows up as a question mark*

EDIT2 - quoi?? Now it shows up as a pound sign! WTF