Most listings are in the $20's per square foot per year. The Berkeley County region is going through a decline in rates. In the last 3 months, the median rate fell $3 per sqft per year. That's a 11% decrease in rent.
In the last 90 days, 34 listings have been listed, which means new availabilities most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. About 150% of the office spaces in the Berkeley County 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 posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,000 sqft. Most properties in this region are approximately 1 floors. Most buildings in this region were built in 1998 and are Class A.