even if a bunch werent stolen from the factory before release, theres no way to know how many are actually out there. all the packets of chips that went past their expiration date wouldve been thrown out by multiple businesses. they may have made 20 for 2007, but thats not to say 20 made it out of their packets. who knows how many were destroyed/laying at the bottom of the local tip or just not opened and discarded by disinterested chip eaters.
i always thought they should be worth more, and i think as time goes on, they will be.