Most listings are in the $20's per square foot per year. The St. Louis County region is going through a an increase in rates. In the last 3 months, the median rate increased $5 per sqft per year. That's a 29% rise in rent.
In the last 90 days, 24 listings have come on the market, which means spaces might be 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 available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,410 sqft. Most properties in this region are close to 5 stories. Most buildings in this market were built in 1926 and are Class A.