Most listings are in the $20's per square foot per year. The Manchester submarket is going through a a rise in rates. In the last 3 months, the median rate rose $3 per sqft per year. That's a 16% increase in rent.
Compared to the rest of the Greater Boston market, the Manchester submarket has smaller rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 237 listings have come on the market, so you'll want to check back regularly for new listings. About 18% of the available leases in the Manchester 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 posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,080 sqft. Most buildings in this region are close to 2 floors. Most buildings in this area were built in 1920 and are Class Class B.