Advise the bookstore when class enrollments exceed your orginial expectations. Let the bookstore know if your class has been cancelled. Recommend that the student purchase their books at the beginning of the semester.
Many publishers have policies which make it necessary to return books before the semester is over.
Your remarks in class affect the way students buy their books. We can only advise students with the information that is filled out on the textbook order sheets. This book is nice to have, but you don't really need it. D. Buy either this one or that one. Communication is very important.