40k seems excessive. say you paid the teacher very well they would get what like 100k a year? So you are saying that 1 teacher can only watch 3 kids? There are entire families with more kids than that.
Heh. If the teacher was REALLY well paid, even for the Bay Area, they would get maybe 80k a year. The starting salary in Palo Alto (the highest in the bay area) is under 50k. A teacher with 10 years of experience will probably be making about 75k.
A preschool teacher typically makes 18-25K a year across the country; I would guess 30-35K is as high as it gets in even the most expensive parts of California (experienced or not).