Wired payment scam
This Con has been about for a while, but the popularity of eBay has brought it back stronger that ever. The con man will post an item on eBay for a great price, something that is sure to get popular around christmas. When the item is 'won', the seller says he doesn't accept PayPal for whatever reason. (Real reason beingPayPal has safety procedures if anything goes wrong with the transaction).
The seller requires it via a bank transfer, the money gets transfer, the item never comes.
eBay has a seller rating service, so the seller usually will get a 100% score from some low transitions, then pull of the scam as many times as possible over a few days, before the ratings can come in.
£20 - £200 (more if they are feeling confident)
How to avoid being scammed?
PayPal is a great service to help protect your money, that's why eBay uses it. There really isn't a great reason not to use it. So if someone explicitly says they can't use it, it might not be worth the risk.