Yay, Ash and Becky!
Where we live, just about every private school is expensive. It stinks. Most of the private preschools are in the $15-20K range. Grade school is generally around $20-30K. Some are even more. The Montessori schools here are in that price range ($15K for half days x 5 day/wk), but I have found our local Montessori schools to be quite punitive. For example, taking away outdoor time is used frequently as a punishment for rule breaking. To me, outdoor time for kids is non-negotiable...and can help improve behavior. But some people *love* Montessori and it works for them and they are very happy. We send my daughter to a Waldorf school, and we're planning to move to a town that has Waldorf K-high school because we absolutely love it. It works out well for us, though, because Waldorf is one of the least expensive options around here. It costs us $8K to send her four mornings a week. When she starts first grade next year, it will be about $13K.
When thinking about private schools, too, don't forget that the schools want your wallets open for fundraising! It's for a good cause, but after writing big checks, it can get old fast!