Most listings are in the $20's per square foot per year. The Kenai region is going through a a boost in rates. In the last 3 months, the median rate went up $28 per sqft per year.
In the last 90 days, 2 listings have been listed, which means spaces most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. About 750% of the listings in the Kenai 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 available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 870 sqft. Most buildings in this market were built in 1993 and are Class A.