My wife and I are going to Boston in August for a work conference. During the conference we'll be staying at the Encore in Boston Harbor - but we'll have Friday to Sunday for personal time.

We want to see Salem, the New England Aquarium, and the Lizzie Bordon house. Obviously we can't afford to stay at the Encore the rest of our stay ($500 a night) so what would be a good town to stay in near Boston that's got some charm to it/good restaurants?

Edit: budget would be under $300 a night ideally with free parking. Again, doesnt have to be in Boston, driving is fine. Just don't want a motel 6 out in the middle of nowhere off the highway.