The typical asking rate per listing is in the $10's per square foot per year. The Monroe region is going through a an increase in rates. In the last 3 months, the median rate went up $18 per sqft per year.
Compared to the rest of the Seattle Metropolitan Area market, the Monroe submarket has less expensive rates, so you should have no trouble finding a great deal in this depreciated submarket.
In the last 90 days, 3 listings have been listed, which means listings most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. 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 2,230 sqft. Most buildings in this market are close to 2 floors. Most buildings in this area were built in 1993 and are Class C.