There are thousands of book stores on the internet that will sell you used books for cheap. If their business is in the same country as yours, you can even avail free shipping, or at least, a reasonable shipping rate. Book lovers from the United States and the United Kingdom are typically at advantage here because a large of number of publishing houses and book stores operate from these countries. But for international addresses, the cost of shipping is usually high enough to prohibit buyers from taking advantage of their services.