If I were making $400,000/year suddenly:
The first year or so I could try to save as much as I could for a maximum cushion before buying anything. It's $250,000 after taxes so the first year I'd take $150,000 and put it into various retirement/savings accounts.
I'd probably go buy a $600,000-700,000 home with no money down. Then get a Tesla and one other "beater" car like a used truck.
$250,000 in take home pay:
Expenses: $45,000 yearly mortgage+ taxes on a $700,000 home (30 year mortgage)
Home Expenses: Assume like $15,000 for heating/cooling/repairs high end
Savings: $75,000/year (at 25 years this will give me nearly $4.9 million at 6% interest)
New Car Fund: $5,000/year
College fund: $10,000/year
Vacations: 2 vacations/year with $10,000 total budget
With that stuff it comes out to $150,000 which leaves $90,000 to play around with. I would not send my kids to private school because I dislike private schools.
$90,000 a year to play around with means being able to take the family out to dinner every weekend, to the movies, to a day trip to the theme park a few times every summer, send the kids to a few weeks of summer camp, buy good food, and buy good clothes and presents.
I assume the goal here is to work and not FIRE. Of course with $400,000 a year you could just find a nice place with a $1,5000/month mortgage and throw in a lot more money into savings and retire pretty fast. I think with the $400,000 salary and saving $75,000 of your take home (and there'd be more money with the mortgage interest deduction but whatever) and getting around $180,000 into your child's college savings (plus whatever it makes) would set anyone up pretty good. IMO.