There is a law that states that any vendor can 
not charge more for certain types of payment like 
credit cards, and that if you are going to accept 
that form of payment, you have to cover the extra 
costs yourself.  That is why when you pay for 
something in a store with a credit card, it 
doesn't cost you extra... they cover the fees.  
It is stated clearly in both Paypal and eBay that 
you can NOT pass the fees on to the buyer, 
because it breaks this law.