We went through some of the same considerations and decided to give our kids a budget and let them decide what to spend it on, whether undergrad, grad school or later for a house downpayment. Too many here limit their thinking to spending the money on education, but there are plenty of other ways to help your kids financially so they can get on in life.
S18 took the in-state flagship route (~$120K for 4 years all in), well within budget, saving some money for grad school. He turned down LACs and other privates with merit (typically $20K-$30K per year) that would have been anywhere from $60K to $100K more expensive. He didn’t bother applying to need only schools that would have been $160K-$180K more expensive (well above budget and therefore requiring loans). His choice wasn’t necessarily the one he would have made if money was no object, but he was clear that there was not going to be a worthwhile ROI from spending more.
D18 won a full ride scholarship (maybe ~$20K for 4 years for miscellaneous expenses) and will have money for both grad school and probably a house downpayment. She turned down the state flagships and other OOS public and privates with lesser amounts of merit aid (all in the range of $100K-$160K). For her it wasn’t a purely financial decision because the course was the best option too, so I think her choice would have been the same even if the cost had been closer to the state flagship level.