The art of taking a idea from inception to shipment isn't cheap. And I'm not talking about the financial cost because that's probably assumed by most people. If you can't afford to front the money to build and ship, you've hit the limits of one of your limited resources. We have two other limited resources, though. Often times, these two resources aren't taken into consideration when planning a new endeavor. Maybe you have the funds available to start a new project, but do you have the time? And what about the energy required to get it out the door?
Every good maker runs the numbers to see if they can afford to build and ship their creation. If enough people buy it, they'll earn a profit. But the costs to your time and energy are a never-ending expense. I won't allow myself to take on more than three side projects outside of my normal work load. And I won't allow myself to stay up late, as that impacts my energy level the next morning when I start work again. If I can't afford it, I don't do it.
The next time you plan some kind of product that you'd like to ship, make sure that you consider all of the costs, not just the financial ones. You'll save yourself from overextending and incurring resource debt.