The typical asking rate per listing is in the $20's per square foot per year. The Kennewick submarket is going through a a boost in rates. In the last 3 months, the median rate went up $10 per sqft per year. That's a 60% increase in rent.
In the last 90 days, 11 listings have been posted online, which means new listings are probably going fast. You'll want to be prepared to make an offer immediately. About 9% of the available leases in the Kennewick 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 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 1,900 sqft. Most properties in this area are approximately 2 stories. Most buildings in this market were built in 2003 and are Class B.