It does sound excessive to me too, though these days it seems one is lucky just to get the job done at dealers, or any auto repair shop. I just had to order a part to fix my car myself (part arrived today) because a local shop installed the wrong part last year. I even told them at the time to use the genuine brand name part, and not a generic because the generic is failure prone. Guess what it failed again 3 days ago, this time I had time to deal with it myself, and sure enough it was the generic brand part.
It seems over and over again, I deal with such things, a few years ago I took a car in to get the fuel pump replaced. Came back 4 days later to pick the car up, and was presented with a $75 diagnostic fee, and was told their was nothing wrong with the fuel pump. I refused to pay it and threw a fit, had them get the general manager, etc. As I did NOT bring it in to get their advice on what the problem was, I brought it in to get a specified part changed, which they did not do even though they kept my car the whole week. Of course changing the fuel pump solved the problem, as I knew it would as that was the 3rd fuel pump I had been through on that car in about 120,000 miles.