Understood. We all do what we're comfortable with. > an incredibly niche problem for an even smaller niche market These are my favorite because no one "big" w

Understood. We all do what we're comfortable with. > an incredibly niche problem for an even smaller niche market These are my favorite because no one "big" wants to get into them. I make a device that converts signals from heavy machinery that uses a specific type of almost-obsolete sensor to let it use a modern control that you can buy off the shelf. A friend of mine used to have a nice side business (was full time for a while) selling a replacement timer for a specific type of industrial printer. I like markets like that. The biggest problem I'd see in your case is that it's a consumer item, not industrial. Most customers just don't want to spend a whole lot unless they have to.