If we took the commuter student options,we are assuming that he could wait and attend a very selective school as an 18 year old grad student.
The undergrad and grad school experiences are very different. Grad students usually don't live in dorms, interact mostly with people in their department, and rarely participate in undergrad extracurriculars such as sports, clubs, student newspapers etc.
I'm not saying your plan is bad, just that going to grad school at an Ivy is not the same as going there as an undergrad.
