i actually don't find this logic to work ... i have a buddy in atlanta who charges $280/hr for a massage and $450 for escorting. he is goodlooking but not a famous porn actor and not especially interesting in the menu department. when he came to NYC to visit, he couldn't figure out why no one was calling him, and i told him it was the pricing - because there are A LOT MORE escorts in nyc .... hundreds or thousands.
Yes, there are more clients and the cost of living plays a part, but if you're in a smaller city and good at it, you can actually charge more.