I don't get this move. The whole point of trading Jaroslav Halak was that Montreal had, in Carey Price, a goaltender who was good enough to be a starter, and having two goaltenders making $6M+ between them was too large an expenditure. Signing Ellis blows that budget and amounts to throwing away much of Price's value.
Kostitsyn may have been a headache in Montreal, but he has some value, and the Habs basically gave him away for nothing. Oh, and Ellis should absolutely test the free agent market. There are a few teams that have a nice pile of money waiting for him.