The typical asking rate per listing is in the $20's per square foot per year. The Greater Portland submarket is going through a decline in rates. In the last 3 months, the median rate decreased $3 per sqft per year. That's a 11% decrease in rent.
In the last 90 days, 549 listings have been posted online, so you'll want to check back regularly for new listings. About 4% of the office spaces in the Greater Portland are subleases, so you will probably have to consider a longer term lease. 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 1,880 sqft. Most buildings in this market are close to 2 floors. Most buildings in this market were built in 1985 and are Class A.