You can sell Pokmon cards through specialist auction houses, such as Cullens of Surrey's trading card auctions, online marketplaces, trading card dealers, and collector groups
This basically works with all the things you want to cheat in and it doesn't require you to have a mountain to be active
Not to mention the multitude of issues players are currently facing with hordes of scalpers scooping up any and all Pokmon cards that they can find, which is subsequently resulting in some extremely expensive Pokmon cards, and shipping delays making it very difficult to get ahold of booster packs and the like
TCG Bulk connects collectors with approved card businesses actively buying bulk, singles, and sealed products
I predicted the Amber and Amethyst Lorcana starter deck was likely to be the most popular build played at prerelease events, and it still is months after The First Chapter was released