Respectfully, choosing to not engage in discretionary spending (buying yearly tennis court membership) does not indicate that an income of $400K/yr isn’t in the top 5% aka upper class.
Choosing as an adult not to visit the Dr. also doesn’t indicate that $400k/yr isn’t in the top 5% of all US income earning households, aka upper class.
You feel it is necessary. It is not objectively necessary to spend $300k on an excellent education. Again, this is a choice.