I think it was the great poet 50 Cent who proclaimed that if he's going to spend money for a woman, he wants her to cost thousands, that way he knows not every guy out there can afford to have her and the mileage is lower. Maybe that gives some insight into the mind of wealthy guys who spend the higher amounts.
That said, I just happen to be visiting Vegas in a couple weeks and have booked with one of my favorite porn stars for a session. Damage was originally $1500 U.S. but she agreed to give her "international rate" of $1200 U.S.. I think you can have just as good an experience with a high end provider as a more inexpensive one, but if you really want to experience a particular provider then treat yourself.