as a domain, barely anything. a name like that would require it to be ranked on search engines with unique content for any plumber in that area to be interested. too niche and very small area. if it was bostonplumbing and not woburnplumbing then it would be better.
I also live about 15 minutes from there, so I can tell you that what I wrote is true. Unless you buy everyone city/town in mass, then maybe you that can be your business. But too much $ and effort for something that isn't guaranteed as its such a small niche.