Is Apple education pricing only for university, not HS, students?
In the past, Apple was very casual about handing out educational discounts. This started to change in 2016 and now as of fall 2017 there is a formal verification process that is outsourced to a verification program that checks hardware purchases as well as discounts to services like iTunes Apple Music service discounts for students.

The TL,DR summary of education pricing is:

Apple Education Pricing


  Available to current and newly accepted college students and their parents, as well as faculty, staff, and homeschool teachers of all grade levels.4


Unless you have been accepted to a college, it is not supposed to be enough.

The terms and conditions page states that the following people are eligible

There is no longer mention of students at the K12 level - only staff at all education levels.