Like anything it depends. How expensive is the private school, what are your hours, what is your spouse willing to accept. While expensive, I will say that a lot of private schools appear to understand the path past high school and into college. I think you'll get better advice about what to do after and I think it will make your kids a more viable candidate for the selective colleges they might be interested in. This again raises the question of whether the degree they move onto will be worth it, and it's a problem that you'll have to make a spreadsheet for. You're paying to keep your kids' options open.