I stayed at the Adams Bed and Breakfast in the Back Bay area in January 2006. It's around the corner from the Berklee College of Music and an easy 5-minute walk to a T station. Nothing super special, but it was very reasonably priced--cheaper than any of the chains I looked at (it's been awhile, but I'm thinking it was in the ballpark of $80?).
I'd stay there again.
I'd stay there again.