On average, listings lease in the $20's per square foot per year. The St. Louis County region is experiencing a a boost in rates. In the last 3 months, the median rate went up $2 per sqft per year. That's a 11% rise in rent.
In the last 90 days, 260 listings have come on the market, so you'll want to check back regularly for new listings. About 4% of the listings in the St. Louis County are subleases, so you will probably need to sign a longer term lease with the landlord directly. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
Even though the median size is 2,630 sqft, there are still 0 leases below 2,000 sqft. Most properties in this market are around 2 floors. Most buildings in this area were built in 1983 and are Class B.