May I offer some tips from a seasoned Ebay seller & buyer with 100% good feedback
Ignore these "will you accept £XXXX for it NOW" offers. Perhaps some are bogus but in every case I have had that or more in the auction. Just reply with "please bid that amount in the auction".
If selling, never give feedback until the buyer has given you his. If it is good, you can give him good feedback (basically, for prompt payment). He will also know this; he will know that if he gives you bad feedback you will do the same to him
Always describe the item very fully, with a number of close-up pictures, write well and avoid spelling mistakes, and make it clear which items you are not sure about. That way, it makes it very hard for somebody to dispute something. A lot of Ebay sellers are close to illiterate and they leave themselves open to somebody claiming the description was false.
Recorded Delivery is traceable but only if the postman bothered to collect a signature. Often, lazy postmen chuck the package in with the rest of the mail, especially on Saturdays. Then, the PO can't trace it... because nobody accepted it. Special Delivery is much better and is tracked all the way. The postman can still lose it but they rarely do.
Paypal is not
guaranteed payment. It can be revoked, even months after the transaction, and Paypal are known to be extremely arrogant when it comes to handling complaints. They are basically not interested. This is what a lot of scammers use; they buy something, and (if it arrives without a signature) then claim they never got it. This scam is very common.
If buying, try to resolve a dispute by private comms before giving negative feedback, otherwise you will get the same from him.