Whoa. The Tsukinos are even richer than I thought.

[hazard]

It looks like everyone has been covered except for Neptune, Uranus, Venus, and Tuxedo Mask.

Neptune is a violinist and noted to be very fashionable. Uranus is a race car driver who seems to own a car and motorcycle in Tokyo, if the pics on the Sailor Moon wiki site aren't misleading. They definitely appear to be rich.

Minako's parents seem to be a salaryman and housewife in the manga, but the anime had her living in London, so her family can afford international relocation. Was her being an idol singer canon or fanon? Either way, she seems to be at least upper middle class.

Tuxedo Mask could afford to go to Harvard in America. Definitely well to do.

I think the lesson to be learned here is that Usagi's mother added a little something extra into the reincarnation spell so that everyone would be well off in their new lives.

Regarding Minato, it's apparently not uncommon for Japanese companies to support or outright subsidize the living costs of useful employees, up to and including arranging a residence for them. I wouldn't be surprised if Minako's father was offered the job in London on the company's dime for a reason the company found useful.

Minako being an idol is canon in the Sailor Moon live action series, where she's dying of cancer IIRC.

And frankly, I've a feeling that a lot of anime protagonists are oddly well to do, if only because that's more convenient to the stories involved.