The typical asking rate per listing is in the $20's per square foot per year. The Willowbrook submarket is seeing a a rise in rates. In the last 3 months, the median rate went up $20 per sqft per year.
Compared to the rest of the Chicagoland market, the Willowbrook submarket has less expensive rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 3 listings have been posted online, which means leases are probably leasing quickly. You'll want to be prepared to make an offer immediately. 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 2,110 sqft. Most properties in this region are around 1 stories. Most buildings in this area were built in 1979 and are Class A.