Most listings are in the $20's per square foot per year. The Boone County submarket is experiencing a a rise in rates. In the last 3 months, the median rate went up $1 per sqft per year. That's a 4% rise in rent.
In the last 90 days, 32 listings have been posted online, which means leases most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 6% of the available leases in the Boone County are subleases, so you will probably have to consider a longer term 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 1,850 sqft. Most properties in this region are close to 2 floors. Most buildings in this market were built in 1997 and are Class A.