I've known lots of people to keep them and they normally dont eat corals, I personaly have a Long Nose Butterfly and he does not touch my corals at all. The thing about copper bands they crash real easy, so i would get your LFS to order you one and if htey dont have a QT tank, they keep it in to make sure its eating and going live for a few weeks before the release it for sale I would not trust them untill you saw it in the store for a week or so and ask to see it eat.