you are right, they would have kept their mouth closed and charge the 700USD and fix the problem as you did. I had a similar experience back in 1998 and they charged a over 400USD for estimate and never even repaired a car. After a hassle they fixed a car with no parts needed and never returned my money. that is why we call the stealers... some of them are very nice though, but it really depends on the people who works there. Many mechanics only know one thing, replace a bad item even if that part is easily fixable. The dealers policy suggest them to do that, new parts means less likely have problems so no warranty repair. what you did was a true savings of 700USD !