Most listings are in the $20's per square foot per year. The Berkeley County region is going through a a boost in rates. In the last 3 months, the median rate went up $5 per sqft per year. That's a 24% increase in rent.
In the last 90 days, 34 listings have been posted online, which means office spaces are probably leasing quickly. You'll want to be prepared to tour spaces as quick as possible. About 9% of the office spaces in the Berkeley County are subleases, so you will probably need to sign a longer term lease with the landlord directly. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
Even though the median size is 4,000 sqft, there are still 0 office spaces below 2,000 sqft. Most buildings in this region are close to 2 floors. Most buildings in this market were built in 2001 and are Class A.