If you book early with a deposit and changeable fare to get the stateroom you want, you can watch for the sales (sometimes only on a specific day) anytime before final payment and change to a better final price...or deal (price plus perks). However, you may lose some of the perks of the initial booking (for example, free gratuities)...it's all a trade off, but has saved us thousands of dollars over the years. We have also made a deal to get discounts from the ta in exchange for doing all the legwork... ie walking in with the info on the cruise, stateroom, and deal that is available at the time.