to me it sounds like you'v answered your own question. You obviously want them to go to the steiner school and your second response seemed very heavy on jusitfying why. I do this when huge amounts of money are involved... like i need to make it clear to myself that it's 'worth it'.
But personally, to me it sounds like you are actually seeking approval to spend that money and make that sacrifice.
Sorry if i'm wwayy off the mark tho! (unbelievably that does actually happen to me! lol).
At the end of the day, only you can answer your question because what i'm comfortable with may not suit your lifestyle etc I think there's great pros and cons to each solution.
Good luck in making the decision!