On average, listings lease in the $10's per square foot per year. The Irmo region is seeing a decline in rates. In the last 3 months, the median rate fell $4 per sqft per year. That's a 20% decrease in rent.
In the last 90 days, 3 listings have been listed, which means new availabilities are probably leasing quickly. You'll want to be prepared to make an offer immediately. 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 3,500 sqft, there are still 0 leases below 2,000 sqft. Most buildings in this area were built in 2007 and are Class B.