The sticker price is quite expensive, how much of that is actually docked off?
In terms of financial aid only (not including merit aid), it depends on a lot of things. Some get a lot of aid, for most middle class and up, they are expected to pay full sticker price unless they get merit aid. Yours is a very broad question.
When running net price calculators with my parents our Net price was generally between 10k (for the most generous schools eg princeton, stanford) to 30k, with most right at 25k. USC was 50k, so it was not generous at all, but that is because my parents own real estate beside the primary home, for some reason USC weight this heavily.