It is not a problem when buying brand new school books for your child every year. However, if cash is not the thing you have in your pocket now and you are on a tight budget, getting second hand school books should not be a problem and an embarrassment to your child too. In fact, many parents who have a few kids do let their children use hand-me-down books.
When looking for school books, there are a few things you must keep in mind and focus on. The most important thing will definitely have to be the edition of the book. Some publishers are smart and take advantage of the situation by updating their edition once every year. However, just compare between the most current one and a book two years old and you'll find there is not much significant differences. I'm sure that a two year old book will suit your child just fine.
The other thing to look out for will then definitely be the pricing of these school books and where to find them. Fret not, cheap school books are everywhere on the net. Practically every online bookstore have cheap school books for your child. It surely will not be a problem finding one!