The typical asking rate per listing is in the $10's per square foot per year. The Mansfield region is seeing a a rise in rates. In the last 3 months, the median rate rose $17 per sqft per year.
In the last 90 days, 12 listings have come on the market, 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 properties in this market are around 2 stories. Most buildings in this region were built in 1967 and are Class B.