Some prime factors that influence rents for the Boston metro are:
 
LOCATION:
*proximity to the “T” (Orange Line, Red Line .. and commuter rail). Proximity to bus routes, I think, is not as great a factor as proximity to the T.
*proximity and distance from Boston .. the overall commuting time to work in Boston
*proximity and distance to some of the large private universities: MIT, Harvard, Tufts
*walkability of the area where one lives. For example, how long does it take to “walk” to the nearest T station, bus stop, food shopping, restaurants, day care, …