On average, listings lease in the $20's per square foot per year. The Maryland Heights region is going through a decrease in rates. In the last 3 months, the median rate fell $3 per sqft per year. That's a 12% decrease in rent.
In the last 90 days, 40 listings have been posted online, which means spaces most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 148% of the available space in the Maryland Heights are subleases, so you might be able to sign a shorter term by taking over a previous lease. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,480 sqft. Most properties in this region are approximately 2 floors. Most buildings in this region were built in 1981 and are Class B.