My problem with so many "service professional" is the double and triple dipping they do in the name of profit, first they charge a labor rate that typically 10-20 times the national minimum wage while paying the actual technician a small fraction of the rate, then the require the service parts be bought through their company, and the parts are often marked up far more than 100%, often these parts are not on the shelf, and must be custom ordered in or picked up from parts houses where they get preferential pricing, then charge for mileage, etc. on top of all that.
Let me relay a recent $300 air conditioner repair deal I had, the problem was the fan on my outside air conditioner unit had failed (blades sheered off laying in the bottom of the unit), I call the company I usually use for air conditioner problems, tell them what the problem is, so they send a technician by to diagnose the problem, he of course did not bring a new fan even though they had the model of the unit on file, so I get charged a service charge for him to show up, I get to pay mileage for him to drive 20 miles to their parts supplier and back with a new fan blade and then I get invoiced $75 for service call, $25 mileage fee to get to my house, $100 for a fan blade (which probably costs them $30) and $100 for labor, counting the time he was on the road going to the parts supplier to get the fan blade that took all of 10 minutes for him to change out.
Ike