Most listings are in the $20's per square foot per year. The South Side region is experiencing a an increase in rates. In the last 3 months, the median rate went up $22 per sqft per year.
Compared to the rest of the Greater Boston market, the South Side submarket has lower rates, so you should have no trouble finding a great deal in this discounted region.
In the last 90 days, 12 listings have come on the market, which means leases 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 available, 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 stories. Most buildings in this area were built in 1900 and are Class B.
Not much of the real estate is used for commercial space, so it might be hard to find office space. Health care is the dominant industry in this region. Most of the folk of South Side work from home. Commuting between 20 and 25 minutes a day is the norm for those who opt to reside in this part of town.