Keep in mind that both wages and rents are higher in SF and not really comparable to the rest of the country.

I know, I'm still curious because a lot of people I knew who also lived there were making like 45k to 80k (8 years ago?) So it's relevant to say their job and how much they were making becauase they might be a rarified class among evev SF...which very much defeats the point of the original comment.

$2400 a month is $29k per year, pretty affordable at the U.S. median household income of $83k. It's not uncommon for people living in big cities to spend a larger portion of their income on rent. And don't forget that many people have roommates.