The typical asking rate per listing is in the $10's per square foot per year. The St. Joseph region is going through a a rise in rates. In the last 3 months, the median rate increased $16 per sqft per year.
In the last 90 days, 12 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 posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 350 sqft. Most properties in this area are close to 2 stories. Most buildings in this market were built in 1981 and are Class A.