On average, listings lease in the $10's per square foot per year. The Billings submarket is going through a a boost in rates. In the last 3 months, the median rate went up $0 per sqft per year. That's a 1% increase in rent.
In the last 90 days, 45 listings have come on the market, so you'll want to check back regularly for new listings. About 2% of the available space in the Billings 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.
The standard measurement for office space in this area is around 1,800 sqft. Most buildings in this area are close to 2 floors. Most buildings in this region were built in 1983 and are Class A.