Most listings are in the $10's per square foot per year. The Westmont submarket is seeing a a boost in rates. In the last 3 months, the median rate rose $17 per sqft per year.
Compared to the rest of the Chicagoland market, the Westmont region has smaller rates, so you should have no trouble finding a great deal in this undervalued submarket.
In the last 90 days, 23 listings have come on the market, which means spaces most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. About 109% of the listings in the Westmont are subleases, so you might be able to sign a shorter term by taking over a previous lease. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,190 sqft. Most buildings in this area are close to 1 stories. Most buildings in this market were built in 1986 and are Class B.