The lowest price on the Greater Boston AirBandB site appears to be $25, and you get several options, most of them single rooms with single beds. One such single room with single bed is in this house off Pearl Street in Somerville. Lest you think you'll feel cramped, well, dig it:
As limited as the phenomenal physical space is, the essential profound space has always been expansive and infinite—encompassing and penetrating all who have passed through with it's light... and when open to receive and willing to feel—the transformations I have witnessed people undergo has been nothing short of breathtaking and miraculous. You're gonna wanna microwave some popcorn just to be safe.
· Our Hotels Week 2013 archive [Curbed Boston]