Direct the potential buyer / buyer to contact you via email to arrange the transaction. IF they are really interested in a photo you have on your site, they won't hesitate in contacting you. Smugmug will only charge their surcharge if your sales are done through their lab, which I think Bay photo is one of them, and I think they give you another option too. I print all of my own photography, or if I cannot do it ( if someone wants something larger than I can print) I handle that too through a 3rd party contractor. That way, I know the quality of the goods going to the customer. Just my $.02 worth.