Yes, cost is the big issue here, especially with 2 younger siblings involved. Please don’t over promise to your oldest at the possible expense of your youngest two. If you are having to look that closely at your budget, you don’t want to get in a bind every year with looking at finances and being worried about increased cost. It’s not uncommon for parents to set a budget with the first , up to instate cost for instance. Truly wealthy parents obviously have more leeway. Figure out a number you can live with and present it to your child. Then, you can go from there- if they want a more expensive school, they might need to take out loans or look for merit. Ideally, top budget is all settled before applications go out.