The typical asking rate per listing is in the $10's per square foot per year. The Sumter region is experiencing a decline in rates. In the last 3 months, the median rate decreased $7 per sqft per year. That's a 31% decrease in rent.
In the last 90 days, 7 listings have been made available, which means listings 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 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 1,430 sqft. Most buildings in this market were built in 1972 and are Class B.