I find that my car runs best and most economical when I'm the only one working on it. Of course, I'm Nazi enough to believe that oil changes and brake pad services should be incorporated into a drivers license test.
Last time I went to a dealer (stealership) for service, I was out of town on business, my wife called me and told me she had a brake light out. I told her to take it to the dealer where we had already spent several thousand dollars that year. They charged her $45 to replace a brake light bulb. Two thumb screws and a twist out fixture and push in bulb. If the trunk is already open and I have a spare bulb in my hand, I can do this in about the same amount of time it takes you to read this.
Needless to say, we have NOT been back to Jim Butler Chevrolet in St. Louis.
What this has to do with the OP is that a rip-off is a rip-off, and most dealers I've dealt with are professionals in this department. Every time we went in for a basic service such as an oil change; they would give us a 4 page list of $800-1,000 of OTHER work they claimed was needed. I came to understand that THEIR favorite location for my car was on their lift.