how much is it to replace all brakes and rotors on an 2011 forester

You can check a repair cost estimate on the Repair Pal website. For all 4 wheels, with new brakes and rotors, I have paid about $800. It depends on the particular car, of course. Sometimes the shop can machine the rotors to get them perfectly balanced (no pulsing when you step on the brake pedal), but in recent years I was told that the rotors have become somewhat thinner than years ago, in an effort to shave weight (for better fuel economy), and so the rotors don't have as much metal, making machining the rotors not as common as years ago.