I have found the Paypal dispute service good sometimes. I bought an SM58 (new) that turned out to be a cheap copy, put in a claim for a 90% return, and finished up with a cheap mic for £4. Not what I wanted, but worth every penny!

At the end of the day however I am clear in my mind that ebay does owe a duty of care to users, and sooner or later someone will sue ebay and win.

Complain to tradng standards and the OFT, nonetheless.