The typical asking rate per listing is in the $10's per square foot per year. The Spokane County region is going through a decline in rates. In the last 3 months, the median rate decreased $1 per sqft per year. That's a 7% decrease in rent.
In the last 90 days, 151 listings have come on the market, so you'll want to check back regularly for new listings. About 3% of the available leases in the Spokane County 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 1,930 sqft. Most properties in this region are approximately 2 floors. Most buildings in this area were built in 1977 and are Class B.