The typical asking rate per listing is in the $10's per square foot per year. The St. Clair County submarket is seeing a an increase in rates. In the last 3 months, the median rate went up $19 per sqft per year.
In the last 90 days, 7 listings have been listed, which means office spaces most likley are going fast. You'll want to be prepared to make an offer immediately. 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 1,500 sqft. Most buildings in this region were built in 2006.