Most listings are in the $10's per square foot per year. The Billings submarket is seeing a decrease in rates. In the last 3 months, the median rate fell $1 per sqft per year. That's a 5% decrease in rent.
In the last 90 days, 38 listings have come on the market, which means leases most likley are going fast. You'll want to be prepared to make an offer immediately. About 3% of the available space in the Billings are subleases, so you will probably have to focus your search on direct office leases. 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 1,500 sqft. Most buildings in this area are approximately 2 floors. Most buildings in this market were built in 1984 and are Class A.