moose;368123 wroteWeek before Christmas is about the lowest but flights are more expensive. Overall first or second week of November (flight and room) is about as cheap as you get.
It's probably better to go in high season when the rooms are packed with bad tourists. Nov to Feb is pretty miserable weather wise too.
If you go to caesars.com you can look at room rates two months at a time and see when rates go lower. Sweet spot for booking is about 4 months in advance.
Do they get increasingly higher as you get closer to arrival, or is there a last minute price drop also?