The typical asking rate per listing is in the $20's per square foot per year. The New Hampshire submarket is going through a a rise in rates. In the last 3 months, the median rate increased $22 per sqft per year.
In the last 90 days, 1552 listings have been posted online, so you'll want to check back regularly for new listings. About 33% of the office spaces in the New Hampshire are subleases, so you might be able to snag a great spot on a short term. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,540 sqft. Most properties in this region are around 2 stories. Most buildings in this area were built in 1957 and are Class Class B.