I have a reservation at a hotel for 9 nights in Waikiki. However, I am considering cancelling a few nights at the end of the trip and trying to get a "nicer" hotel for the last couple of nights as a treat. I have no idea if there would be any availability at the beachfront hotels, and what the price would be. Is there any chance I might get a deal if I wait till I book it there in person? Or is it really expensive to do it that way? We are staying at the Ohana East and are considering getting a few nights at the Sheraton or Hilton etc.