@itsgettingreal17 - One of the OP’s issues was:
By restricting the full pay offer to only the five hardest schools to get into, one can offer all your children equal opportunity without much fear that you actually be called on it. However, in the unfortunate event that all of my kids got into a HYP, I would be very, very happy to delay my retirement to cover the cost.
The interesting thing is my kids at this point have little interest in HYPSM. Most of their interest has been in the safety, match and reach merit schools they picked out.