Demand is determined my the pleasure one gets from it. Supply follows that demand. So the pleasure determines everything else. Do i need to make drawrings for you?
No, demand has to do with the amount of people seeking sex workers services, and the amount of sex workers providing those services.
The better the product the higher the price. It allows you to be on the high end of that supply, to which there will be less demand for due to the higher price.