You have as much right to your own original work as anyone else has to theirs. Later today I may invent a new kind of telephone, just as someone else in the far corner of the globe invents one just like it. We both achieved the same goal with completely independent means and thought processes. We both have a copyright on the work we created. As long as you can prove your product was your creation you have a copyright on that work. If someone files a patent subsequently, and your product is in the public domain (you have started selling it), then you have the defence of due dilligence that they missed your product when they performed the Search. Yes, there are Copyright Agents that will file your design for a fee - but we were talking here of doing something on the cheap.

Life is short, get it on the market, make some money and move on with something new. We all dream of the killer invention... the big one that will make us all millionaires... trust me, it's a lot easier to produce a hundred little things, making ten or twenty-grand on each one, than wasting your life dreaming of the big one.