Most listings are in the $10's per square foot per year. The Oak Lawn region is seeing a decrease in rates. In the last 3 months, the median rate fell $5 per sqft per year. That's a 22% decrease in rent.
Compared to the rest of the Chicagoland market, the Oak Lawn region has lower rates, so you should have no trouble finding a great deal in this discounted region.
In the last 90 days, 2 listings have been posted online, which means listings most likley are 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 2,010 sqft. Most properties in this region are around 2 floors. Most buildings in this region were built in 1975 and are Class C.