We actually use it here at UAB quite frequently. We have a Henry review lecture series once a week where we go over a chapter in Henry and answer questions from the review book. So, I think that it is worth $50. Someone else can answer if it is actually indicative of CP board questions, though.
I've used it, though I didn't buy it. Questionbooks keep me from sinking too far into a stupor on CP rotations. Lobby your chief resident to add it to the residents' library