How exactly do they check? When I buy movie tickets, I simply show them my student ID card and call it a day. Do I need to get anything signed by a faculty member or bring them transcripts?
Sometimes when you buy it at Apple-affiliated store on a university campus, you can get lucky and they'll give you the discount even if you're a highschooler
Since you have a student ID, you shouldn't have a problem. But if it's not a uni one, just ask a college student/teacher that you know to go with you to buy it and use their ID.