The typical asking rate per listing is in the $20's per square foot per year. The Johnston submarket is going through a a rise in rates. In the last 3 months, the median rate went up $2 per sqft per year. That's a 10% rise in rent.
In the last 90 days, 20 listings have come on the market, which means office spaces most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
Even though the median size is 5,000 sqft, there are still 0 leases below 2,000 sqft. Most buildings in this market are approximately 1 floors. Most buildings in this market were built in 2002 and are Class B.