Personally I think with most high end hotels it has to do with supply/demand and when their peak season is.
For example, I have stayed in the Ritz-Carlton, Palm Beach, for $175 a night, in July.
That very same room costs about $600 more in January, when the peak season is for Palm Beach.
I see this a lot in NYC for example when luxury hotels have low rates ($475 at the Peninsula, $380 at Carlyle) during promo times, but I have also seen the same rooms go for $900 a night or more.
Personally I become spoiled by this, as I am sure many people do. But hey, in theory, a luxury hotel is supposed to be on the higher priced side, so I always tell myself not to expect the super low rates, and if I get them, it's icing on the cake.
I don't think there's any difference honestly in a $300 room and a $600 room, with the expetion of size, rooms/suites, but service wise you should be getting and should be expecting the same at those high price points. What I personally loathe is when a mediocre hotel has prices that seem outlandish for the type of hotel it is. Personally I would never pay $450 plus for a normal Hilton or normal Hyatt property, not even in NYC or Paris, unless I absolutely had to.