Question

Help please. I have a 1996 Chevrolet Tahoe, 5.7L,gas, on which the brake lights do not work. The flashers, running lights and front lights work fine. A shop checked it out and tells me that the combo switch for the high beams, hazard, windshield washer and guide lights is bad. This is NOT the multifunction switch on the steering wheel. This is the switch located above the brake pedal or so I am told. I am further told that this is a box of switches ....not a single switch.....which is clustered under the dash panel and must be totally replaced even tho only the brake switch is inoperative. Does this make sense? I am told that the switch is $750 and labor is $200. Is this possible? Where can I buy this part on the internet. What is the part number? And, can you tell me a step by step order of replacement? Thank you. This is my first time to try your service. Barrett Clisby