Hehehehe for hardcover, you pay for the cover since it's fancier and thicker than paperback. The hardcover book is normally bigger than a paperback book, and the paper quality is way better than that of a paperback. I bought one paperback book back then and let my cousin borrow it for her flight to France and Italy (the Angels and Demons one
I wanted her to trace the steps they had in the book. Unfortunately, she finished it on the way home. She regretted not to listen to me, as most people would be at some point in their lives LOLOLOLOL). And she gave me back a wrinkly, junky book after a month. I never wanted to buy paperback books again.