Most listings are in the $20's per square foot per year. The Greater Boston region is going through a a rise in rates. In the last 3 months, the median rate increased $1 per sqft per year. That's a 6% rise in rent.
In the last 90 days, 901 listings have been made available, so you'll want to check back regularly for new listings. About 4% of the available leases in the Greater Boston are subleases, so you will probably have to consider a longer term lease. 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 4,230 sqft, there are still 0 leases below 2,000 sqft. Most buildings in this region are approximately 2 stories. Most buildings in this market were built in 1964 and are Class A.