Even though I'm not as involved in it now as I have been, I'd probably have to say that my most expensive hobby is opera. It almost scares me when I think just how much money I've spent over the years buying music scores, CD recordings, video recordings, and tickets to live events (not to mention the money my parents spent on my voice lessons). However, it is something I love, which I find beautiful and which gives me a lot of enjoyment and peace. I feel that very little of the money I spent was wasted (although there were a few recordings and performances that were really bad!).