The guys in the Workshop hear this a lot. Personally, I find this very amusing. Maybe with time it'll get tiresome, but I'm still new to S.
My answer has always been, "it's a hobby". If one is looking for an investment, it's not model trains. So if you see something different you want to try - a new scale, gauge or prototype - go ahead and try it. Yes, it's going to cost you some money, but all hobbies cost money so just go with it and enjoy.