The typical asking rate per listing is in the $20's per square foot per year. The Milwaukie region is going through a a boost in rates. In the last 3 months, the median rate rose $11 per sqft per year. That's a 74% increase in rent.
Compared to the rest of the Greater Portland market, the Milwaukie region has less expensive rates, so you should have no trouble finding a great deal in this undervalued submarket.
In the last 90 days, 1 listings have been made available, which means spaces are probably going fast. You'll want to be prepared to make an offer immediately. 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 1,500 sqft. Most properties in this market are close to 2 floors. Most buildings in this market were built in 1988 and are Class B.