The typical asking rate per listing is in the $20's per square foot per year. The Mystic region is seeing a a boost in rates. In the last 3 months, the median rate rose $25 per sqft per year.
In the last 90 days, 1 listings have been listed, which means new availabilities most likley are leasing quickly. You'll want to be prepared to make an offer immediately. 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 900 sqft. Most properties in this market are around 1 floors. Most buildings in this area were built in 1986.