This, unless you treat the hobby more like a business or make it a business. I'm building a collection that represents about 2% of my net worth. I go in with eyes wide open, knowing that I or my heirs will likely lose something like 20% in transaction costs, probably more on my medal collection. But I enjoy the heck out of the hunt, the research and the challenge of getting the best value for my money; completing a set or goal; looking at my coins on quiet evenings like Scrooge McDuck; organizing and displaying my collection; visiting with fellow collectors and friendly dealers; learning about new, unfamiliar aspects of numismatics; tying my coins and medals to history, learning the history of the coins themselves, who designed them and why they were made. Others enjoy learning about the coining process and what can go wrong, collecting errors; cherrypicking scarce or rare varieties or die states. (P.S. I also play golf. The wife plays competitive bridge. Both are expensive and guaranteed to be poor investments.)