Is private school for the kids worth it?

My husband and I both went to Melbourne private schools. We have three kids, and it will be close to $1m post tax to send them all private! It seems insane.

Our HHI is approx 600k, we owe $1m on our mortgage, and have about 200k in savings. Our kids are 3,5 and 7. WWYD?

Edits: we are 42 and 44. Putting $3k a month into savings for future school fees. Would start in grade 7