Rover owners: Broken exhaust, costly?

Recently, whilst driving, I heard my exhaust getting louder and louder, and I thought to myself "wow, removing the volume control valve has actually worked", but alas, no. I looked underneath and the metal bands that hold the exhaust box has snapped and this has resulted in pulling apart another part of the pipe (as seen in the pictures). Two questions then:

1) Is this damaging to the car/cat/exhaust

2) Is it easy to fix and will it be expensive