We need a "raped by the dealer" thread but it would probably use all the space on the hard drive.
I once brought a Subaru Outback to a dealer for a recalled head gasket leak and I casually asked how much to tighten a rattle in the door. The recalled fix was free, of course, but it cost me $52 for the "estimate", which was $250. I took it to a paint/body shop, he popped the door panel, tightened a bolt, charged me $20 for the 15 minute job.