On average, listings lease in the $30's per square foot per year. The Charleston submarket is seeing a decrease in rates. In the last 3 months, the median rate decreased $6 per sqft per year. That's a 16% decline in rent.
In the last 90 days, 37 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 available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,650 sqft. Most properties in this area are approximately 2 stories. Most buildings in this area were built in 1985 and are Class A.