Totally normal and the rust on the callipers can easily be removed, if it bothers you, I see this on all cars in Ontario.
What I would be more worried about is paint chips that haven't been taken care of and the condition of the undercarriage, if the car was never oil sprayed, I would pass on it because with rust, it's not the stuff that you can see that will get you in the end, it's all the areas hidden away that can collect water that will rust first.