The typical asking rate per listing is in the $10's per square foot per year. The Roselle submarket is going through a an increase in rates. In the last 3 months, the median rate went up $1 per sqft per year. That's a 7% increase in rent.
Compared to the rest of the Chicagoland market, the Roselle region has lower rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 7 listings have been listed, which means leases are probably going fast. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 800 sqft. Most buildings in this area are around 2 floors. Most buildings in this market were built in 2005 and are Class B.