We used to go looking for old comic books on Clark St. in Chicago during the early 1960s. Most of the used book shops were located just north of the Chicago river bridge. There was ABC Magazines and William Ostfeld rare books, comics. Ostfeld had a a wide range of comic books from the 1940s and 50s which included the first Superman comic 1939 hanging in the front window. He was asking $ 25.00 for it at the time. Those were fun times.