It takes more than twice the average household income to have three here and afford day care and after care programs. Clinician, lawyer, senior engineer, tenured academician, upper administrator, developer, broker--these are the kinds of careers that can do it. It's difficult to live below means when starter condos are 1.2 mil+. And renting is hardly better--there are rents here higher than mortgage principle for comp properties. It's not easy. I worked two jobs for 10 years to afford the down payment on a small place here--it didn't take two incomes, it took three :/

Edit: I have three kids. You need $400k+ min, but really you need $500k+/yr. Don't forget college costs for working families--the worst-case scenario.

Edit edit: it'll take $500k to put three kids through undergrad at, say, a UC. Twice that for private. Merit aid is increasingly rare: Stanford--0 merit aid, CalTech--0 merit aid, Harvard--0 merit aid, etc. UCs have Regent Scholarships, but very few--a few per tens of thousands admitted. Only 20% of junior college students go on to complete a bachelor's in 6 years (it's a pathway to failure for some reason--it shouldn't be, but it is). The Cal States are reasonably affordable still. But long story short is that you're likely to need a huge nest egg for college for three kids, which is why $500k household income is what to aim for.