Glad I found this thread. Just got quoted $1900 for a clutch install at a shop near my house. The guy quoting me was babbling something about a dual mass flywheel that requires special machining so they just replace them with a new one since it's so hard to get them machined and the new ones are like $600, yadah yadah yadah. Yeah, right.... I might have been born at night, but it wasn't last night.
Why does one shop charge more than another? Because they can!