If he cared if "cash-strapped school districts" got it for free he would give it to them... its his film. Keep your stupid film my kids will be out sick that day.
Your kids might be out sick that day, but the teacher will just make them watch it at a later time because they will be quizzed on the film...and if your kids refuses to watch the film, they'll get a zero and sent to the principal's office and suspended for 5 days.