Shops get charged 2.5% on credit card transactions and about 50p on switch card transactions. Do they charge you the extra 2.5% or 50p to make up for it? - no, so to me, why should i as a buyer pay the 4% or whatever, and also what right do i have as the seller to charge it.

If i signed up to paypal (which i arent) i am agreeing to their terms, and if that means that I get charged the 4% per transaction, then i've agreed to it as part of the service.

Also, cant paypal take the money from your account again if theres something wrong with the credit card (ie stolen / copied) or if the buyer says theres something wrong with the item / never received?