There are a lot of young, beautiful girls in NYC for every taste that will do everything but anal for $300 or less. I don't know why these girls charge $400/hr but if they can get it more power to them. At a certain level, more expensive is not better. Maybe it's the very cool tats one of them has.
Better environment, low volume, previews from girls who join in if they like you, a quick snack before, during, and possibly after, being able to converse so the quietness doesn't create awkwardness.
People do seek all those things besides the physical part too.
And their rates have been 400/hr for a while so it's not like it's an outrageous price that no one is going for, otherwise they would have dropped the price.
It's been that way a while, so guys are seeing them at that rate.