Buying Children's English Books 😅

I didn't spend a lot of money having a trip, but I started using it up after coming back. I have no kid at home though I bought children's (English) books, even 8 books. Five books before the trip, and three today. The local used bookstore was selling some new books - a lot of same ones, and on the side of the books there were some marking like dotting or crossing out. Is there something wrong with them? Seems like the publishers wanted to clear out their stock.
It was 'a discount sale', so looked around and bought five thick hardcover books for older teens, not for a very young kids. (The rest of three are my taste of books - the Peanuts series. Two of them had stickers. lol But today when I visited there again those books were all sold out. I should've bought a couple of each before. lol)

Among those hardcover books, all I know is just Wonder that I wached a movie before. (I intentionally chose 'signed copy.') No idea about the rest, but most of them must be awarded somewhere. I didn't choose all of them, but just some for reading easy and quick, reviewing my English reading.