On average, listings lease in the $20's per square foot per year. The Northampton submarket is going through a an increase in rates. In the last 3 months, the median rate went up $24 per sqft per year.
In the last 90 days, 3 listings have been made available, which means new listings 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 on the market, so finding a space for a small business might be tough.
Even though the median size is 3,540 sqft, there are still 0 new listings below 2,000 sqft. Most properties in this region are around 2 floors. Most buildings in this region were built in 1920 and are Class A.