Most listings are in the $10's per square foot per year. The Humboldt submarket is experiencing a decline in rates. In the last 3 months, the median rate fell $2 per sqft per year. That's a 13% decline in rent.
In the last 90 days, 13 listings have come on the market, which means new availabilities are probably leasing quickly. 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 1,600 sqft. Most buildings in this region are close to 2 stories. Most buildings in this area were built in 1951 and are Class C.