I guess its a question of what you think is worth spending money on, but for me, a great sci-fi book is always worth it. And this book is a great sci-fi book. I've read other books about neanderthals and I've read other books that claim to be mystery sceince fiction, but this book has them all beat. You can't wait to get to the next scene and you're never disappointed. It moves along quickly and keeps you guessing. What more can you ask from a book? I don't for the life of me understand what a few of these people are talking about - this is the best damn money I've spent on a book in quite a long time! Let's hear more from this writer!