When I think of this question, I think more of "really expensive because of service level", not because of location.

During high occupancy periods, you can spend several hundreds per night on marginal accomodations in name brand places. I have also had rooms in nice places where the actual room would have gone for over $1000 a night, easily. Yet I wouldn't consider them "really expensive hotels" because while the service was decent and the rooms were nice, they weren't true luxury experiences.

I have stayed at a few places that have bordered on true luxury (where you can do no wrong, where every request is met with the proper and immediate attitude). Its quite nice. But until $ is not an object, I can't imagine spending $ on it on any regular sort of basis.