Bladeswitcher that is where you and I disagree. When I negotiate a lower price than what you ask, it is because I won't pay your asking price. If we agree on a price, my position is that how I pay for it is a different question and is my sole choice...Geo
And I factor in method of payment when considering a price offer. A deal happens when both parties are satisfied with the terms. It's really not complicated.
If I have something priced for $1,100 and you propose paying $1,000 I may ask how you're paying. If you say cash I know that I'm going to receive $1,000. But if you say you're going to use your credit card I know I'm actually only getting $970. If I don't want to accept a further $30 cut I politely decline your offer and we go our ways. Again, it's not complicated.
Now, if you're willing to pay my $1,100 price I would be foolish to object to credit card payment.
