Sadly, Catso is mistaken,.
S.75 of the Consumer Credit Act does make the credit card liable for purchases over �100 if something goes wrong, but there must be a direct relationship between the seller who accepts the credit card payment, the buyer who uses the credit card and the credit card company which is used by the buyer and accepted by the seller.
When the card is used in a Paypal transaction, there is no direct relationship between the credit card company and the seller. So the credit card company has no legal obligagion to refund. Some credit card companies offer this protection as part of the terms and conditions, but you must check before you rely on it to fund a dodgy eBay purchase.
http://www.early-warning.org/viewnews.php4?id= 75
The additional credit card protection is nothing whatsoever to do with this sort of transaction.
I suggest you google reputable companies and see if you can buy the item at a similar price directly from a reputable store.
However, if you are determined to buy from eBay, make sure that PayPal's buyers' protection up to �500 applies to that seller.