Here's a rundown of the cost of tuition at many of the city's popular private schools. Please keep in mind that nearly all private schools offer some sort of financial assistance to families who can't afford tuition.
$16,377 Ada Clevenger
$18,800 Live Oak
$19,350 The San Francisco School
$19,550 Brandeis Hillel (K-7; goes up in 8th)
$20,200 Convent and Stuart Hall
$20,540 San Francisco Friends school
$20,805 Marin Country Day School
$21,090 San Francisco Day School
Thanks to the parent who helped me track down these numbers! Also, please note that many of these numbers go up after kindergarten or in middle school. And let me know what I've left out. Thanks!