Many properties do not list the square footage so it is difficult to obtain information based on square footage. There are so many factors involved with value beyond square footage that it really is not a good indicator of price, especially in the city when many properties are so unique. Simple square footage calculations cannot account for any of the other factors that reflect value including: the level of update, proximity to loud streets, trains, facing a brick wall, a top floor vs. a garden, all things to consider (and many more), parking options, central air, in-unit laundry and outdoor space.
You can search by closing prices by neighborhood at http://chicagotribune.public-record.com/realestate/search/cook. However, you will only see the address and the price not anything to do with the features of the home listed above. Consult an agent for more detailed descriptions of comparable properties.