@newbeee2012,
I agree with Linkat, definitely check.
I know that people who live outside of our district are allowed to attend if they pay a certain amount of money. I forget what that amount is, but it's less than most private schools and in most cases less than the housing differential would be. (Houses in a nearby district that is not nearly as good tend to cost less, in large part for that reason. People often move here for the district and are willing to pay more.)
I don't know details though of whether they have caps on how many people can do that per year, what the amounts involved are exactly, etc.