We were in a very similar situation with our school choice. We had met with the principal of the local public school and walked away feeling that they would not really meet our son's needs. I went to an open house at a private gifted school, and walked out feeling like we had to do whatever we could to have him go there. It is kind of out of our financial league as well, but we are trying to make it work. He started Kindergarten in September, and is thriving. We are absolutely gaga over his teachers and the school.
Everyone's situation (and child) is different, but for us, it was the right choice. While the "cons" pointed out earlier are real, there are "pros" that are just as real...
