My target for each of my kids, was to have enough to send them to an in state university for 4 years, by age 18. With my oldest at age now, we were able to hit that goal.
If they go to graduate school, they will borrow. If they get AP credits, dual enrollment credits or scholarships, they can put that towards a more expensive undergrad, or use it such that there’s money left over for graduate school so they can reduce the amount borrowed.
Both of my kids will start college as juniors with 2 years credit already (AP plus dual enrollment) due to being smart and motivated, which helps.
You want your kids to have some skin in the game. Because unless you’re a multimillionaire, smart kids with expensive educational tastes could set you back 1/2 million dollars or more, each, for a private undergrad plus medical (or other graduate) school.
It helps to work in mays to motivate them to keep costs and borrowing to minimum.