NPR recently ran a story on the excellent The Pushcart War by Jean Merrill. Perhaps as a result, the out-of-print book will now set you back at least $48 on Amazon. Bookfinder.com, however, a federated search engine, quickly returns a link to a more understandable $12.94. I have to wonder if a spike of interest, related to the author's passing, drove up the price on Amazon despite the cheaper versions available from other sellers--and what this indicates about Amazon's marketplace power. (Merrill's other works don't seem to have suffered from the same amount of runup in price.)
P.S. Children's books for the Kindle are a great thing. Talk about being willing to trade off price for convenience!
Also, for delightful transformative uses, check out these dramatizations/trailers/etc., now available on YouTube when they formerly would have been hidden inside a single classroom.