Most listings are in the $10's per square foot per year. The Springfield region is going through a decline in rates. In the last 3 months, the median rate fell $11 per sqft per year. That's a 37% decline in rent.
In the last 90 days, 11 listings have been made available, which means spaces most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. 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 2,500 sqft. Most properties in this area are approximately 1 floors. Most buildings in this market were built in 2006 and are Class B.