The typical asking rate per listing is in the $50's per square foot per year. The Portland region is experiencing a a rise in rates. In the last 3 months, the median rate went up $50 per sqft per year.
In the last 90 days, 0 listings have been made available, which means spaces most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. About Inf% of the office spaces in the Portland are subleases, so you might be able to sign a shorter term by taking over a previous lease. 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 1,140 sqft. Most properties in this market are around 2 stories. Most buildings in this region were built in 1979 and are Class B.