I have had the pleasure of having been a parent that has had a child in Prep School and who also played 16AAA and 18AAA. There are many reasons that go into letting your child leave home at an early age. My son went the Prep school route as a freshman and played varsity with his prep school as a 15 year old. He was playing against some 19 Y/Olds and did well in hockey and in school. That being said, he missed home terribly and at the end of his freshman year came home. He ended up playing 16AAA and 18AAA and has grown tremendously over that period of time. Not only has his hockey skills improved with the great coaching that we have here in SoCal nowadays, his schooling has been excellent and we as parents have enjoyed the extra two years we got to spend with him.
His exposure to scouts at the Prep level was great. They are around the schools and tournaments and if you son/daughter are good enough they will be seen and seen alot. But his opportunities at the AAA level have been just a good because they are playing top notch teams "Tier One Elite league" and scouts from Prep schools to all Junior leagues go to these showcases as well.
If I had to do it all over again, I would have him played up to 16AAA at home and let him attend Prep school if he wanted to. If he didn't go to prep school and stayed home to play 18AAA, it is NOT a bad choice. It depends again on the child and his or her mindset, but no one should think that just because you child does not go to prep school that they do not have a chance to play juniors, that is not true. My son is playing 18AAA and has had many offers to play Juniors next year and from top leagues, as well as contacted by D1 college coaches. At the end of the day if they have the skills and are playing in the right leagues that have exposure, they will be seen by the next level coaches.
Cost is always in the equation and it's true very few get to the next level, but paying for prep school and having your child be away from home at 15-16 or paying the money to AAA, I would rather have him home and still have the exposure to go to the next level if he is good enough. Both options are good and should be looked at carefully before any decisions are made.
At the end of the day we as parents feel good about how it played out and we have enjoyed the hockey ride with our 4 children immensely. Its teaches them so much of what is needed to be an adult and the friendships with the parents and coaches along the way has been awesome.