Where can I get these and what are the costs of them in Chicago?
The Chicago Trolley & Double Decker Tour Co.'s website has a ton of great info. You can find the downtown tour stops at this link. They stop near the Skydeck Chicago, Michigan Avenue Bridge, Block 37, The Art Institute of Chicago, the Hilton Chicago, Museum Campus, Sheraton Chicago Hotel & Towers, Navy Pier, Water Tower Place, and Hard Rock Cafe Chicago.
You can purchase tickets online here ahead of time for a discounted price, or you can purchase them from The Park Shop at 11 N Michigan Ave (right near Cloud Gate aka The Bean) or from The Explore Store in the Block Thirty Seven shops building. A day pass for adults is $35, but you can also but a night pass, or a 48 or 72 hour pass.
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You can get a 1-day transit pass at any CTA station. At each station, they have very easy credit card stations that will provide 1-day passes.
I'm not sure the cost any longer, but you can get them at CVS or purchase at the train stops...