I used to work there about 15 years ago and they had a really great outlet store (a real outlet store with seconds and samples - not like the ones in outlet malls) at their headquarters in Brighton, MA and another one at the factory in Lawrence, MA. They've grown/changed a lot since then so I'm not sure if they're still there. I do remember that they didn't advertise it much, it was pretty word-of-mouth. I'd call them to check.
Our outlet mall doesn't have a New Balance store but they do have several shoe stores that carry all kinds of brands. I can check for you next time I'm there if you want.