[StevieG]

Generally, booking through a hotel is cheapest. Plus, when you book through the hotel directly, you have much greater flexibility for canceling if you happen to find another a better rate after booking.

Which is what you should do. Vegas hotel room prices fluctuate practically by the hour. So best to use a site like Travel Axe to find something you like, book directly through the hotel, then look every week or so to see if something better comes up, then jump on that.