Travelzoo offers the Chicago 5-Attraction CityPass for Adults for $94. (It costs the same directly from CityPass, but a $1 processing fee applies.) That's $94 off list and the best deal we could find on this pass. Use this pass at any time over a 9-day duration to gain access to five Chicago tourist attractions including the Shedd Aquarium, Skydeck Chicago, the Field Museum, Museum of Science and Industry or John Hancock Observatory, and the Adler Planetarium or Art Institute of Chicago. Book this travel deal by August 14.
Of note, a kids' ticket is available for $79. That's $80 off list and another price low.