I came over here with two buckets labelled Money and Experience.
I told myself that when either of them is full then it is time to move on, but since I arrived here I now realise that there is something a lot more important; a third bucket labelled 'Health'. Should that one start to empty too quickly then it is time to go.
In short, how much is your health worth? We all have a choice, it is just having the balls to cut the ties and move on when you feel the time is right.