Stilly -

Ref eBay's Then, you could for example offer a discount to buyers who pay by your preferred method

Note that since the new bankruptcy statutes were enacted in the US recently, companion changes made it a technical violation of a US Federal Statute for any commercial seller to offer a discount for paying cash instead of by credit card, or for offering a discount for use of one credit card instead of another, if the seller takes any credit cards at all. The seller may specify that only certain cards are accepted, but the "price" cannot be changed to reflect the method of payment.

Most credit cards previously included that in the terms of use of their cards, but information from my local newsrag (not always 100% reliable, of course) indicated that it is now US Law.

John