The author is pointing out that spending gobs of money on expensive educations is no better than the public education that is either free (high school) or cheaper (public colleges.)

I've lived this, too. My parents sent me to a private high school, and later when I found rankings in my state, my private high school was no better (or worse) than the free one in town. I was no better or worse off, I probably would have kept most of the same friends, and probably would have gotten into the same colleges.

Then, my Dad pushed me to a "fancy" private college. The professors were just so-so, and I should have transferred. (I didn't know better.) Later I found rankings and my "fancy" college ranked poorly, but the public college nearby was ranked significantly higher.

After graduating from college, I bumped into some people from high school, and we all agreed that our guidance counselor gave us horrible college advice. Had I gone to the public high school, would they have pushed me towards the better public college? I have no idea.