Buying textbooks for college?

Hi. I am starting college in the spring, and I am currently in the process of buying my books. I get financial aid, and I have money left over to buy them- however, I do not have a lot, and I might not be able to purchase all four books that I need. However, when I went on the school's online book store, there was a "rental option" for books.. it is significantly cheaper than purchasing the books. Now my counselor, and the financial aid office never recommended, or brought up renting out books, instead of buying them.

Is it better to buy books, or is it okay to just rent them, and turn them back in at the end of the semester? Tell me what you think. Thanks!