Most listings are in the $10's per square foot per year. The Florence region is going through a an increase in rates. In the last 3 months, the median rate rose $18 per sqft per year.
In the last 90 days, 6 listings have been listed, which means office spaces most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. About 50% of the office spaces in the Florence are subleases, so you might be able to find a shorter term or below market rent. 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 1,270 sqft. Most properties in this area are approximately 2 stories. Most buildings in this area were built in 1960 and are Class A.