There can be a huge difference between a good honest mechanic, and a good honest mechanic that knows how, and has the tools to work on late model VWs. And regardless of how many people tell you, most people (including mechanics) don't get a grip on that concept until they experinace it first hand. I can assure you, you are not the first to make that kind of mistake. As the old GI Joe cartoons used to say at the end, "and now you know, and knowing is half the battle."
My dad was a mechanic so I grew up turning wrenches. I always thought of myself as a good mechanic . . . maybe too slow to make a living at it, but at least I could work on my own cars. Then we got a 96 Passat. Everything I've touched on that car has turned into an educational experiance and mistakes can get expensive in a hurry. I've had my share of "do it myself to save money" projects and ended up spending twice what someone with the knowledge and tools would have charged me.