On average, listings lease in the $30's per square foot per year. The Charleston region is experiencing a a rise in rates. In the last 3 months, the median rate increased $5 per sqft per year. That's a 18% rise in rent.
In the last 90 days, 133 listings have come on the market, so you'll want to check back regularly for new listings. About 94% of the listings in the Charleston are subleases, so you might be able to sign a shorter term by taking over a previous lease. 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 1,640 sqft. Most properties in this region are around 2 floors. Most buildings in this market were built in 1981 and are Class A.