Emphasis on cheap. I need some stocking stuffers. There’s plenty of souvenir places out there, but most of them seem horribly overpriced.
If you can get downtown, walk up and down State St., or Michigan Ave. south of the river. There are any number of little shops that sell exactly what you’re looking for - plastic Water Towers, snow globes. etc. Happy shopping!
TAFFY! Then send me some! 
Any downtown Walgreen’s will have tons of cheap tacky souvenirs. So will the airports (but probably not quite as cheap).