The typical asking rate per listing is in the $20's per square foot per year. The Bristol County submarket is going through a a boost in rates. In the last 3 months, the median rate increased $22 per sqft per year.
In the last 90 days, 18 listings have been made available, which means listings most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 6% of the listings in the Bristol County are subleases, so you will probably have to consider a longer term lease. 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 450 sqft. Most properties in this region are approximately 2 floors. Most buildings in this market were built in 1900 and are Class B.