I can give you this advice from the few kids I have coached that have gone onto private HS or preps. 99% of the conversations went exactly like this
School/Coach: "would your kid be interested in coming to _________ to play hockey ? "
Parents: "yes, but we cant afford that for high school !"
School/Coach: "well, what do you think you could afford ? "
Parents " Probably around(insert low ball offer here) or we were paying $4000 for private middle school "
School/Coach: "SO you would play for 4k ?"
School/Coach : "He's in"
Parents to each other: "****, we should have said 2k"
Even the selects schools with huge endowments are not going to throw around financial aid like that. Yes, they will give deep discounts to some kids and almost free rides to other exceptional candidates , but certainly not so brazenly or at the coaches discretion