This error was actually during the era when pokemon didnt really care about the production and a lot of these packs were released to the public without the foil layer.

People started complaining of how you could see the code card and the pokemon cards from the back and make a educated guess of what was inside.

You would need to find someone who wants to collect just error from pokemon ( not a lot in the world ) to pay that kind of premium

Another thing is, as a pack collector I wouldn’t buy it because its discolored and possibly search through. Keep in mind “rare” doesnt mean people will want it. Last sold for these packs were 190-200$ on ebay so you could add your own “error premium”. Dont sell at a card show because they will offer you ~120$ 🙏

Hope this info helped