I think we are talking about two different things. The total cost of attendance at different schools before any merit or need based aid will vary widely between schools, but yes each family starts at the same COA at the same school.
The COA is on the colleges websites and in the financial aid packages. Like the sticker price of a car.
Only knowing merit offered by other schools does not help figure out the ask for this family.
U1 is could be COA at $60,000 total with $15000 in merit and no other aid. Cost to family is $45,000.
U2 with a total COA of $75,000 and $35,000 in merit and $5000 in need based gets the same family to $35,000.
U3 with a total COA of $65000 and $30000 in merit gets the family to $35000 as well.
U4 is only Total COA at $34,000 and no other aid is offered. Family is at $34,000 annually.
U5 is 90,000 per year Total COA and has offered acceptance with merit and need of
of $45000. The cost to the family is $45,000.
If U1 is the top choice, they need to ask for merit of $10,000 to get to a similar final cost of 3 of the 5 schools. They do not say U2 gave us $35000 and U3 gave us $30000, we need twice as much merit. It is easier to explain where your bottom line is and that you need an additional $10,000.
If the most expensive school gives the most aid that does not mean another school is going to provide that same amount of aid, but they may get you to the same bottom line. In this example U1 and U5 cost the family the same amount.