Most listings are in the $10's per square foot per year. The West Chicago region is going through a an increase in rates. In the last 3 months, the median rate rose $20 per sqft per year.
Compared to the rest of the Chicagoland market, the West Chicago region has less expensive rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 9 listings have been posted online, which means new availabilities are probably going fast. You'll want to be prepared to tour spaces as quick as possible. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,490 sqft. Most buildings in this area are around 1 floors. Most buildings in this market were built in 1979 and are Class C.