My suggestion would be to take care of you health. There are companies that can afford to pay you for each and every extra hour of on-call, but they won't necessarily look for you well-being. Having extra time off sounds nice, but on the other hand it will affect the other stuff that you usually have to do at your job.

I was hit by on-call duty pretty hard at some point in my career. I was sleep deprived and was not able to execute on my regular tasks. This also lead me depression and increased my anxiety. Even though I've started to work on my issues with therapist, I was not able to recover and was let go.

Remember about taking care of yourself.