In the past I was thoroughly keen on old US coinage...things such as the Trade Dollar, Morgan Dollars, Walking Liberty Half Dollar e.t.c. intrigued me. It didn't take long before the hobby got really expensive. Granted, it's nowhere near as costly as my current hobby in photography, but eventually even I was worried to be spending so much money on a coin.
However, the fun factor was there. Even today, I still take a closer look at any of the flea market stores that sell coins. I notice what sort of fakes they sell and tell myself, "Hey, how cool...it looks almost like the real thing!"