On average, listings lease 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 rose $24 per sqft per year.
In the last 90 days, 106 listings have been listed, so you'll want to check back regularly for new listings. About 66% of the available leases in the St. Louis County are subleases, so you might be able to snag a great spot on a short term. 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 10,000 sqft, there are still 0 spaces below 2,000 sqft. Most buildings in this area are around 3 stories. Most buildings in this market were built in 1961 and are Class B.