>Why spend $149.99 on a Biology textbook that only has 3 chapters you need?<p>Unfortunately, that's not how textbooks are written. Unlike music albums, where an artist invent 1, 2 or even 3 good songs, and then must fill the album with lesser songs, most chapters in a textbook are needed.<p>Further, chapters of a textbook are often related or dependent on each other; it's doesn't make much sense to buy selected chapters from textbooks.