World prostitution prices posted below and the money paid to prostitutes is quoted in U.S. Dollars. The rates and prices for sex are collected from various reports, such as reports by criminal justice programs and public health programs, as well as news reports on where to find prostitutes . How much the prostitutes charge is often based upon the sex worker being a victim of human trafficking.
Also interesting are the black market prices for contract killings, kidneys/organs, meth, cocaine, exotic animals, and AK-47's from around the world.
Not exactly a scientific study.