If you can replace the brake pads and rotors on your car or other vehicle yourself then it will be much cheaper.
Brakes pads usually cost around $20.00 to $40.00 per set and rotors are around $50.00 to $100.00 a piece depending on the vehicle so if you replace the brakes pads and rotors yourself you could do it for around $300.00 or less.
You do have to bleed your brakes off though when changing out the brake pads and rotors.
If you have no knowledge in the brake system then it's best to have a shop do the brake job which could cost $600.00 to $700.00 and sometimes even more depending on the shops overhead and hourly rates.