Without further ado, below is what we spent for a year of preschool. Some of these numbers are estimates, and it's possible that I missed something major, but I think this is pretty accurate. Also note that these are the numbers for her last year of preschool. The prior 2 years were more expensive because at the preschool Star went to, tuition is higher for the younger kids.
Tuition - $1595 per month x 11 months = $17,545
Winter Camps - $450 x 2 weeks = $900. The $450 number is an estimate. I usually seem to spend around $450 for a week of camp. Sometimes it's a bit more and sometimes it's a bit less. (When she starts 2nd grade, she might go to sleepaway camp which will triple the $450 per week estimate, but we can wait a few years until we get to that.)
Summer Camps - $450 per week x 4 weeks = $1,800. See note above.
Random field trips, various days off, auction, gifts for teachers... - $500
Morning Helpers - $2,000. We have a Cal student come to our house most mornings at 7:30am to finish getting Star ready and to push her in the stroller to school. Scott and I leave for work at 7:30am, and this is the system we've found that works for us.
Total Annual Cost = $22,745
Star is about to start public Kindergarten, and when she does, I plan to start posting about how much public Kindergarten in Berkeley actually costs. I know that it's not really free, but it's some mystery as to what we will actually be asked to pay for.