The typical asking rate per listing is in the $20's per square foot per year. The Spokane County submarket is going through a an increase in rates. In the last 3 months, the median rate went up $7 per sqft per year. That's a 41% increase in rent.
In the last 90 days, 177 listings have been listed, so you'll want to check back regularly for new listings. About 50% of the available space in the Spokane County are subleases, so you might be able to snag a great spot on a short term. 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 2,000 sqft. Most buildings in this region are close to 2 floors. Most buildings in this region were built in 1977 and are Class B.