I think it's pretty much been summed up here.

Ayers Rock is a tourist destination; there is no reason to go there unless you're a tourist. Airline (QF) logic: cashed up US/EU/JP tourists will pay anything, therefore we won't offer any cheap fares.

My advice: skip the rock. But then again, I'm a jaded Australian who thinks Steve Irwin should turned into stylish-yet-affordable leather handbags.