If you are just changing the brake pads or shoes it would be cheaper to replace them yourself. Brake pads or shoes will cost about $25.00 per set for basic performance needs. If you already have the tools or have access to the tools it will be cheaper to replace them yourself. As for estimates I've seen some places advertise brake service at 80.00 per axle. This would only be for basic pad or shoe replacement. If other parts are needed there will be additional cost.