Most listings are in the $20's per square foot per year. The Missouri region is going through a decrease in rates. In the last 3 months, the median rate decreased $0 per sqft per year. That's a 1% decline in rent.
In the last 90 days, 645 listings have been listed, so you'll want to check back regularly for new listings. About 3% of the available space in the Missouri are subleases, so you will probably have to consider a longer term lease. 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 2,260 sqft. Most buildings in this area are around 2 floors. Most buildings in this market were built in 1984 and are Class B.