Then, honestly, you're wasting your time. People, especially those who are very concerned about the condition of their items, are (more often than not) able to secure another copy for close to what you'd be asking for a new label.
Besides, you could take out the Nintendo seal of quality and replace it with something, a dead giveaway for a repro.
Also, would you be running 4-color process on these labels? Without it, they're not going to look all that great(coming from someone who works with printing every day).