There's an interesting factor to the discussion on this that no economist, projectionist, etc... can measure and estimate and that is the "value" of a trip to a Disney Park perceived by an individual. This is why many on the boards don't see a significant problem with price increases, as they are so into WDW that they'll pay as much as they need to to experience it. Because it's hard to argue "value", people use comparisons to other consumer goods, other theme parks, and multi-day
ticket prices.
Unfortunately for Disney, there aren't too many people like that ($464 for an AP is nearing my limit) and, as another poster alluded to, the market won't bare $180 for one-day at MK, and Disney will eventually have to adjust to the market.