One of the best transactions on ebay was an Ibanez 7 string guitar that I helped my son transact (£x00 of HIS money). Couldn't have been more straightforward. Lovely guy and fantastic musician from Glasgow. Beautifully packaged etc

One of the worst was a fake memory stick. I got the money back.

Middling was the spider capo I bought recently. Full refund and the seller was happy that I kept it. Gave him a good rating for dealing with it well and since then has changed his advertising.

But I think I have only every bought 70 something things on ebay