I bought these books for my son as a present for good grades- he asked for them. They seemed expensive to me but how many kids want physics books? These are nice solid books and I expect he'll have them for the rest of his life. They have a feel and a heft that seems to convey the essence of the subject. He's happy and all I can say for myself is the day these books arrived he opened the box took them out and looked at them, then he walked over and without a word gave me a hug. Yes, I love this purchase.