I never buy if feedback is below 99%, unless exceptional circs. I have 100% 0n 6800 feedback.
I go by what the feedback is about, I had an account once where people got jealous and was buying and giving bad feedback, the reason I was better than them and they did not like it, when buying things on ebay use common sence, if th person is emailing something dont pay p&p, if there p&p is over inflated question why in regards to the price you pay.
Why we are on the subject of ebay, never click a link from email, always type in the address, same goes for paypal, if you are not in the know you could well get cuaght out, that is one of the best tip for you will ever get