Plan price is a function of (1) the number of books, (2) book page count, (3) student population, (4) plan duration, and (5) number of schools.
Number of books goes up, the base price per book goes down.
Smaller books cost less and bigger books costs more.
For student populations:
- below 475, small school discounts are applied
- between 475 and 1000, no price changes
- above 1000, price increases with every student