Yes I've usually bought books before school started, as I checked the course and reading list at the University's website before term started. It's better to think ahead and beat the rush for the bookstore once the course actually starts. But you're always entitled to a refund if you give the assistant a receipt for the books.
When you were in college or is in college, have you ever bought books before school started and if you did but than found out those are the wrong books according to the syllabus, how would you deal with it? Would you ask for a refund?
I have. I bought the books then the teacher changed his mind. I just did and exchange and paid the difference. Of course the new book was more expensive! We would not have it any other way would we?