My 2020 committed recently to a mid-level D1. The school communicated the offer in terms of an exact dollar figure for all four years. Of course, as others have noted, they could walk away at a future point in time. But that's the chance you take, and it's where my son wants to go so he jumped. If I thought there was a reasonable chance they would rescind the offer down the road, I would have urged him to wait, but this school does not have that reputation. Time will tell if I was right.