Private schools also receive the bulk of their revenue from private contributions and fees.
(Plus another $8k one-off fee to apply/enrol a child)
The article is glossing over the fact that the crazy amount of money this school has is coming from parents.
$32,000 to $47,000 per year per kid pays for a lot. Assuming these fees were frozen for the next 13 years (which they obviously won't be), it'd cost a parent $525,284 per kid to send them to this school. Plus all the other costs like uniforms, books, excursions etc.
That's the other thing about these schools - the school fees themselves basically just buy you the privilege to send your kid there. But then you still get ripped thousands more for pretty much everything else. And it's not like their uniforms will be cheap. You pay extra for any sporting activity, you pay extra for electronic devices, it's just a money grab from beginning to end.
And at the end of the day, the only thing you can say with certainty is that your education was expensive. But was it worth it? Was it better than a public school?
Well, if you want to go by HSC results (and many people would consider that the yardstick) then there's many private schools among the top schools, although there's also lots of government selective schools, including the very top 4.
The highest-ranked private schools are probably academically selective in some way too, though, so I wouldn't think we can attribute the results to just the teaching there. And even if they don't, kids of wealthy parents have an academic advantage throughout their education because of factors tied to their parents' wealth (aside from being able to afford private education).
I'd imagine, though, at least some of the vast amounts of cash these schools have must go towards attractive wages for good teachers and more of them (smaller class sizes), and both of those things make a difference.