On average, listings lease in the $10's per square foot per year. The Willimantic region is going through a a rise in rates. In the last 3 months, the median rate increased $16 per sqft per year.
Compared to the rest of the Greater Boston market, the Willimantic region has smaller rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 1 listings have been made available, which means new listings most likley are going fast. 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 1,300 sqft. Most properties in this area are approximately 2 floors. Most buildings in this region were built in 1925 and are Class C.