Congrats, those are interesting books you got. For me, it is really worth to scour the used books area of a thrift shop because it is much cheaper than to buy new ones. Most people get rid of them once they´ve finished reading it. I love to browse books in our local secondhand shops. There are so plenty to choose from, the only thing is most books were written in German. Oh and yes, I love Michael Crichton, he is brilliant with his plots. Enjoy your books!