I like the idea. It's breaking the mould of standard marketing ideas to more of a quirky way. A golden ticket would be cool because it makes the opening of a NIB pin even a little more exciting (at least for a moment) just like in the Willy Wonka movie just with chocolate, but it's a good point

(no gold certificates in the machines cause the pinball machine dealers would nick them out etc).

Something like this could create a bonus incentive for some to buy but ultimately the individual would have really wanted that pin in the first palce because 6K + is a large outlay in the first place. So similar to what robm said I don't think the primary affect will be that it influences someone to go out and by a NIB game.

So IMO:

Bonus - Yes, I wouldn't knock it back.
Another good form of marketing to collectors - Yes
Incentive that makes or breaks buying NIB pin - Not really but still like the idea.