Capt_coconut, July at the Polynesian is Value season, while October is Regular. The fairy tale package will be more in October, as will the rack rates.
I'm not 100% sure why the deluxe resorts are in Value season over the summer. Perhaps because many families go for the all stars or moderates? Those resorts have regular season all summer long.
October is a popular month for conventions, golf, the food & wine festival, etc. - all pretty popular with guests who choose deluxe resorts.