Wow, I'm amazed that there's such a low rate on the door. If anything, I'm usually blown away at the $799 or whatever crazy rates that are posted as the maximums.
My impression, as a non-lawyer who just travels a lot, is that those legal signs must be a throwback to days when hotels would bait-and-switch the unwary traveler, or an attempt to limit the gouging that occurs when a special event is in town (but I wonder if all those Marriotts in Phoenix really had $1000 maxes posted on their doors).
I secretly thought a good way to limit the ridiculously high limits on those door postings would be to charge the hotels property taxes based on the maximum revenue at maximum occupancy. That would force them to balance their desire to be able to charge a lot a few times a year with the fact of life that for the vast majority of the time they won't be able to charge anywhere near the max rate.
Ah, well. That was a long and rambling reply, but I'm as curious as the rest of the lot to see what the hotel tells you!