You have no idea what you're talking about. A public garage in a cheap part of SF will run you $200-$300 a month, per space. A small non-luxury one-bedroom is about $3500 a month right now, maybe closer to $4,000. A week of groceries at Trader Joes will set you back about $80 a person, if you're frugal and you know how to cook, and you eat nearly every meal at home, and you like leftovers.

Eating out at a restaurant that isn't a taqueria or in-n-out is about $20-$30 a person at the low end. A drink at a bar will set you back at least $6, and probably more like $12-$15. Getting your one-bedroom apartment cleaned once a month will cost you about $100-$150.

I don't have children, but not-rich friends who do have told me that unless you live in a "good" neighborhood and/or your kid can be bussed long distances, you really have to consider paying for private schools, and that's something like 20k a year, per child.

So one-bedroom, one car of parking (not counting maintenance or the cost of the car), eating out at a modest place once a week: $3500 + $200 + $320 + $120 = $4140/mo. That's frugal. Want a kid? Dramatically more.

And please add saving like crazy for retirement, because for people under 40, there will not be any Social Security money left. And, if you have children, start saving for college (at $250K/child for private college and $120K/child for state college).

While $250K is certainly a comfortable level for a single person, it is not as outrageous as it may seem to people outside of the really high-cost areas in the US.