Allston, Brighton are cheap but infested with college students and mice. So don't go there. One more thing, you need permits to park on city streets. If you live in somerville, you have to get their permit ; if you visit other town then unless the street is unassigned, or has meters its resident only st and you will need overnight permit and so on. Out of state plates are not provided the same permit unless you change the plates. Depending on where you will work you might not even need car.