The return on your investment must be worth the time, effort, and what overhead if any is involved. I know several collector/investors that are into guns and a few other things. Being a collector allows for the very long term investment (years). None of these guys come even close to making a living at it, so its a hobby that may one day pay for itself if they ever manage to sell it all off. With few exceptions one must be a manufacturer or retailer to make money at selling to the end consumer. If it takes 4 hours of effort to make $20.00 then that less than minimum wage. I hope that the four hours is spent doing what you like and not just to make money.