I have two NLD kids, and at the middle school level we had to make the same decision. We were able to find a local charter middle school with small class sizes (17 to a class) and a really nurturing supportive staff. This saved us from having to fight the district for an out of district placement. (my older one was in the district middle school for 6th & 7th grade and it become more and more difficult to meet his needs)
For high school, we found a small supportive agricultural HS that has been a good fit for our older son. The younger one really needed something more specific to his needs, and attends a VERY small private special education HS at public expense.
$10,000 per year is way on the low end, price-wise, for a special education school... around here, they run from $25,000-45,000 for day schools. (even the private NON-special ed schools are in the $25,000 per year except for parochial schools) But remember, even if a district can't meet your child's needs in-house, they are required to provide a Free and Appropriate Public Education. This means that if they can't meet his needs, they have to pay for him to go to a school that can.