There was a long wait list to get in the basic computer science class and I was on the bottom of the list.  On the first day of class, the teacher already assigned us homework.  I didn't want to and couldn't afford to buy a super expensive textbook for a class I'm not guaranteed enrollment.

So, I did my studying in the school bookstore.

If you saw a girl sitting under the book shelve studying, that was me.
I did buy the textbook though, after I was enrolled in the class.

Of course, I bought a used one.