I don't see how you could deem it to be anything but a business cost ?:| 

The fact that it is only incurred after the buyer purchases is not really relevant because many costs are only incurred after an item is purchased. Just as I don't want to pay more than I have to for my packaging supplies or postage cost I would like to keep the fees for my payment processing as low as possible.

And yes the buyer ultimately pays it as part of their invoice total, but the less I have to dispurse to my suppliers (including paypal) then the better my bottom line, and that is the whole point of being in business is it not?

Anyway, the point is moot because sellers can't opt out of accepting echeques and PP fees are not likely to get lower any time soon 🙂