Most listings are in the $10's per square foot per year. The Old Saybrook Center submarket is going through a a rise in rates. In the last 3 months, the median rate rose $15 per sqft per year.
In the last 90 days, 7 listings have been made available, which means listings are probably going fast. You'll want to be prepared to make an offer immediately. 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 1,200 sqft. Most properties in this area are close to 2 floors. Most buildings in this region were built in 1973 and are Class A.