I've even seen the hotels prepaid guaranteed cheapest no refund rate to be higher then rates on the same page. But yes, I've seen conference rates, wedding rates, etc be higher at times.

I think when the rates were quoted that may not have been the case, but once those rates are set they never drop, should the hotel need to adjust rates down because of availability, regular rooms will fall, the quoted rates will be high.

I've also been to conferences where the conference holders got all pissy when you mention they didn't have the lowest rates, as they guaranteed the hotel a certain number of rooms at the higher rates, and guess what, nobody wants to pay higher rates for no reason anymore.