Data from Redfin and Zillow - Home Prices, Sales & Inventory
These might be helpful - especially for those who do not have access to MLS. If you have other resources that you use, Please post and share with the others.
Downloadable Housing Market Data From Redfin
You can add/remove different suburbs of Chicago such as Naperville, Wheaton etc. In fact this is useful for all the markets that Redfin is in.
United States and 50 Largest Metro Areas: June 2017
From Zillow