The typical asking rate per listing is in the $20's per square foot per year. The Spokane region is going through a decline in rates. In the last 3 months, the median rate fell $0 per sqft per year. That's a 2% decline in rent.
In the last 90 days, 114 listings have been listed, so you'll want to check back regularly for new listings. About 1% of the listings in the Spokane 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 available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,640 sqft. Most properties in this area are close to 2 floors. Most buildings in this market were built in 1965 and are Class B.