Idk, I think you would know more about this than I would, but I figure any gift, used or not, should be better than no gift, so still a plus. On the other hand, though, if it's obvious you read it (like all the pages are slightly separated - that happens whenever I read a book), it might seem kinda tacky. So idk. And also what Sen said, they might enjoy opening a brand new book. And when you read a book, it leaves your energy imprint on it. They might prefer their book's energy to be neutral.