The typical asking rate per listing is in the $20's per square foot per year. The Johnson County submarket is going through a a boost in rates. In the last 3 months, the median rate went up $3 per sqft per year. That's a 14% rise in rent.
In the last 90 days, 12 listings have been posted online, which means listings most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. About 8% of the office spaces in the Johnson County are subleases, so you will probably have to focus your search on direct office leases. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
Even though the median size is 3,000 sqft, there are still 0 leases below 2,000 sqft. Most buildings in this market are around 1 floors. Most buildings in this area were built in 1966 and are Class B.