Is it customary for the dealership to add fees ($2K) to the stated price in car gurus?

My daughter recently went to see a car that was listed at $10,900 and when
she arrived at the dealership, they tacked on another $2000 for some kind of
dock fee (which they said is usual and customary, and that car gurus only
gives the base price of the car, without considering what the dealership pays
on top of that price to get the car ready for resale. Is this true, or is it just a
gimmick to try to milk us for more $ than the listed price??