When you're going to a highschool that is more expensive than most colleges you expect to receive a top notch education. If the students don't receive said education then nobody would send their children there and then the school would close and wouldn't make any money.
For example: I go to the most expensive college in Virginia, and when parents pay such a large sum of money to send their kid to be educated they expect them to receive the best education money can buy. Why else would someone pay $37,000/year if they could receive equal education and opportunities for $3,000? In addition to top notch professors, I also have at my disposal many other benefits that students at other schools don't have which make it worth the money. (While this may be the most expensive college in VA, it's also rated as one of the top value colleges in the nation due to what they offer)
It's a sad unfairness, but you're paying for both prestige and education - both of which are valuable assets in life.
Note: This isn't to say that what I'm writing is the gospel or anything, as large inexpensive state schools constantly output very brilliant individuals who go on to do great things and make tons of bank - but what I said is the theory behind pricier education.
We actually have a seminar coming up on campus soon about whether or not public education should be abolished. I don't think it should be, but I think I might go check it out to see the arguments.