We've had a number of threads here about e-bay and the general consensus seems to be 'Use your head, be careful and you should be OK'
Seeing a seller's rating helps a great deal and you can usually - but not always - get a feel for the seller through their wording and Ad presentation.
I've bought about five things from E-Bay, never had a problem. Two of the sellers actually phoned me up during the transactions, both seemed like good peeps.
I don't know what protection, if any, E-Bay offer for broken deals or faulty goods, perhaps other more enlightened users can help here.