In addition, public schools, on average, are more expensive than private schools. The story focuses on a handful of elite private schools in the $30,000-plus range. Such schools do indeed exist, but they are atypical.
I live in DC. This year's Census Bureau report on public school financing showed that DC public schools have total revenues just shy of $30,000 per pupil. That is far in excess of the tuition at all but a handful of the local private schools, and is not far short of Sidwell Friends, etc. DC is the most expensive system in the country, of course, which just goes to show that money alone doesn't buy quality.
Good observations.