I bought several books in my first year, the local charity book shop has a great collection of textbooks for my course (several former students and lecturers donated them, as well as ex-library copies). Although my situation was rather different.
We were specifically told not to buy any books, as it is a waste of money (all the necessary material is given to us, and there a lots of copies of books in the library for further reading). I am glad I do not feel that I have wasted any money, I love all of my books. However I do feel bad when students are pressured into buying books they don't need. Hopefully you can sell yours at the end of the year and make some of your money back.