One thing to keep in mind is how high salaries are across the board in San Francisco. According to sfgate and us news best jobs, registered nurses earn an average of 122K a year in San Jose, and dental hygienists earn 106k in San Francisco (software developers fall between these two groups).

So this means a nurse and dental hygienist couple earns a family income of about 230K a year. They probably aren't buying in palo alto, but they aren't priced out of other nice suburbs. The sad thing is that most of the high salary is dumped into the housing market (and child care, which can be 25k per kid, which becomes a huge issue when you need two incomes). I guess it all depends on how much you love living here (if you have the right setup, it actually is pretty incredible, but you truly do pay).

It's not easy, but you don't have to scratch your head and wonder "who are these people". A two income middle class couple is in striking distance.