@Joe I don´t want to imply that prostitution is the fault of men, it is the fault of an entire system of thought and belief. I agree with you that there are a lot of instincts at work. But if women were more open to having sex and not asking for anything in return, the demand for prostitution would drop considerably. There is more prostitution in sexually repressed societies.
Women are trained to be prostitutes from a young age. I myself was--I was supposed to get a good education, learn to play tennis, cook well and in return I would get a husband who would pay for the lifestyle my mother thought I should have. We are talking about wall street bankers, not turning tricks on the street corner (the "one client" model of prostitution, or traditional marriage). When I traveled to Cuba I for the first time became the John, as I had more money. This caused me to do serious self examination and question the beliefs I was taught from a young age. It was very painful for me to realize that for my parents my education was just an excuse to get a better john, that I would often go on dates with men for the dinner, make them pay for drinks, or I would dismiss men in a rude manner--all behavior that is considered normal in the modern world.