Most listings are in the $30's per square foot per year. The Seattle region is going through a a rise in rates. In the last 3 months, the median rate rose $1 per sqft per year. That's a 3% rise in rent.
In the last 90 days, 487 listings have been listed, so you'll want to check back regularly for new listings. About 13% of the listings in the Seattle 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 posted, so finding a space for a small business might be tough.
Even though the median size is 5,600 sqft, there are still 0 office spaces below 2,000 sqft. Most properties in this region are approximately 3 stories. Most buildings in this region were built in 1982 and are Class A.