Most listings are in the $10's per square foot per year. The Sioux Falls region is seeing a a rise in rates. In the last 3 months, the median rate rose $1 per sqft per year. That's a 5% rise in rent.
In the last 90 days, 93 listings have been made available, so you'll want to check back regularly for new listings. About 2% of the available leases in the Sioux Falls 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 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 1,930 sqft. Most buildings in this area are around 2 floors. Most buildings in this market were built in 1990 and are Class A.