You are right, people are using the internet for pricing and because of economic times. We try never to use their parts. We explain that we can't warranty the part and they would pay twice for the repair. Years ago, we did use a customer's starter. We ended doing it three times. She had purchased a really cheap inferior part. I can't say we never use customer parts, but usually only bulbs or wipers. Another instance, yesterday a customer came in and had a problem that another shop had done. As usual, we tell the customer to take it back to the shop that did the repair. He said I can't they are out of business. He was not happy that we were going to charge him $100. for diag. Service Writer explained that shops that don't charge for diag and markup on parts, can't stay in business. Shops have to make a profit on parts and labor and to take care of the customer's problem, then with a good warranty. Another instance customer with a BMW brought it in for a check engine light. We read the code and did the 1st step of diag. Tech said it could be several different items, we needed to go to additional testing, pin point testing. Customer refused. He went online and said he could get the parts for a 1/3 of our cost. We told him without further testing, we couldn't be sure which parts were absolutely necessary. He took the car and said he would do it himself. He ordered the parts and did the repair; it did not fix the problem. He called back complaining that we had diag the car wrong. Service Writer explained that is why we needed more money for diag time, which he had refused. He said now I have to package the parts back up and pay shipping and my car is still not fixed. These are just a couple of stories. After many years, one learns that there are some jobs you don't want. You can't win. You are in business to solve the customer's problem. Shop owners must pay for the overhead, employees, equipment, schooling, all the rest and still make a profit for the owner.