Not sure about this as circumstances change and things change. My oldest went at a time when many school offered merit aid. With my youngest, many of the same schools have turned to need-based aid and have stopped offering merit money. Does that mean he has to go to in-state public. We are also in a somewhat better position due to the improving stock market. Does Kid 1 get to decide what kind of school all the others go to?
What is one kid does not go to college of doesn’t finish? Is he entitled to that tuition money?
This is easy if you have kids that all have the same level of ability, need, and drive and the financial picture is the same in each case. When kids are very different or situations change, it is not always easy to be fair.
I am with those that think the money belongs to the parents (assuming it is earned income, not grandparent money). If there is a windfall saving, why wouldn’t the parents be entitled to use that extra money to make their retirement years more comfortable rather than handing it to the kid that chose a less expensive college.
If the cost is really different and if there is anything left, perhaps we would adjust the inheritance accordingly. However, I would not hesitate to spend those additional funds if needed for our own well being.