I have heard of far too many independent 'billybob' mechanics that are either crooks or incompetents. There is even a brand of 'quick change oil' places that is featured on YuoTube as systematically ripping customers off. [Starts with the letter'J']
I can forgive the higher priced charged by a dealership IF they do the repair right. One Ford dealership has tire monkeys that use an impact wrench to secure the wheel nuts-one stud got stripped and it took forever to get the nuts off cause they were so tightly torqued [and i am a big beefy guy and not 100 pound woman] they cannot touch my tires or brakes a name brand shop does that, starts with the letter 'F'