Not strictly on topic, but 2 observations:
In the wake of the Charlie Sheen & friends hooker scandal, Heidi Fleiss was asked why some of the most attractive, famous, eligible bachelors in the world would have to pay for sex. She replied trenchantly: “They’re not paying you for the sex; they’re paying you to go away afterwards.” (Found in Steven Pinker’s wonderful book “How The Mind Works”)
In a course on negotiating strategy, Roger Dawson cites the “call girl principle,” namely that “the perceived value of any service declines precipitously once the service has been rendered.”