The typical asking rate per listing is in the $10's per square foot per year. The Kansas City region is going through a a rise in rates. In the last 3 months, the median rate increased $1 per sqft per year. That's a 8% rise in rent.
In the last 90 days, 40 listings have been made available, which means spaces are probably going fast. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,520 sqft. Most buildings in this region are close to 2 floors. Most buildings in this region were built in 1967 and are Class B.