I also live in Western Mass, and my dealer seems to always have a couple around his lot, new and used. Someone is buying them.
Actually, I bought one myself, although I haven't had a lot of opportunity to use it. It seemed to work pretty well in my hard pan clay and rock soil when I tried it out. I think our soil type makes it all the more important that the box blade be heavy and well built.
Now, if you've got very large rocks, I can see where it won't be all that useful. Most of ours are about grapefruit size or larger.
~Rick