The typical asking rate per listing is in the $40's per square foot per year. The Groton submarket is going through a a rise in rates. In the last 3 months, the median rate rose $42 per sqft per year.
In the last 90 days, 4 listings have been made available, which means listings are probably leasing quickly. You'll want to be prepared to make an offer immediately. About 25% of the office spaces in the Groton 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 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 150 sqft. Most properties in this market are approximately 2 floors. Most buildings in this market were built in 1983.