That's a nice idea but what continent are you based on?
There are generic enclosures for the different Arduinos, but you could offer custom enclosures and design. If you were fast and did it at a reasonable price, you could make some money.
I'm interested. The most significant issue in my project has been the enclosure. I am using a 20x4 LCD and it's the width that is the sticking point. In the end, it seems like I might have to simply sit down with template making material and rough something out, then send it to a 3D printing outfit.
I have a 3D printer if you want to PM me with some specifics, I would be willing to help.