Raspberry Pi as basis for commercial device?
I would probably say that the Raspberry Pi would be great to test everything and make sure your project will work. Of course, nothing's stopping you from using it too but if you want to sell to the public, the Raspberry Pi might be hard to get enough of. Plus, it would probably cost more because of the added functionality you won't need, and not fit an ideal form factor for your project. You would have to design your project around the computer controlling it (Raspberry Pi) instead of the other way around.

It would help a little more if we knew the nature of your project, but I understand that may be confidential.