Yes, I really like this forum, but could never do a case study because I'd be blown out of the water. I'm the people old timers here complain about. Our AGI was $193k last year, but will be lower this year ($165k) because I downshifted, and by the time we pay taxes, we spend, um, a lot. Roughly:
$2k high school tuition,
$3k housing / maintenance /utilities,
$2.1k healthcare (self-employed so deducts from AGI),
$1.5k food inc. restaurants, kids' school lunches and dh's lunches, (I know, I know)
$.5k cars/maintenance/public transport,
and about another $1k on everything else (travel, entertainment, clothes, garden).
And then fed and CA and SE taxes.
But, we have aging and in one case terminally ill parents in other states and countries requiring regular visits, and 2 kids in high school - one in private, one with learning differences. I'm downshifted to help care for both these responsibilities (and also working on switching careers - to post-retirement work I love). I also wear the only mustache in the family, and I started proselytizing to the family too late to turn the Titanic too hard.
So, I believe in mustachian principles, but we're relying on past 'stacheing, our absurd housing market, kids eventually launching, and (sorry, but it's true) future inheritances to eventually drift us into FIRE.
(Edited for clarity)