When I was in London a few months ago, I was approached by a prostitute as I left a club on one of the back streets of Soho. Mainly interested in checking the rate of exchange I assure you, I asked: "How much?"
"It'll cost ya twenty quid" replied the tart.
"American Express?" I inquired.
She gave me an appraising look and said: "You can go as fast as you like" .