I'm all for it. But i think that if you go ahead with the project, in addition to a small asterisk or otherwise noticable difference, there should be a 'checkpoint' of sorts.

If a person wants a copy of a label for a high-profile cart, like Stadium Events or another sought-after game, they need to request the label, and you need to provide them with some kind of unique identifier. Open the dictionary and pick a random word. The buyer would then have to write that word on a piece of paper, and take a photo of it with the cart they want to replace the label on. That would cut down on the number of assholes trying to profit off your service, not to mention trying to rip off unsuspecting people.

You could also limit each person to one label per title, and track it in a database or spreadsheet.

I'd really like to see this come to fruitition.