UPDATE: CBR has been informed that the information on Heritage Auctions is inaccurate as the "yellow cheeks" Pikachu card up for auction is not a first-edition base set card but rather the Unlimited variant. This version of Pikachu is also the lesser valued of its two variants, comprising roughly 80% of the variant run with "red cheeks" Pikachu accounting for 20%. This article has been amended accordingly.
Since its debut in 1996, the Pokémon Trading Card Game has become increasingly popular not just among players of the game, but among collectors of rare and valuable cards as well, and one such collectible was auctioned off by Heritage Auctions for over a thousand dollars. As per Heritage Auctions, the card in question is a Base Set Unlimited Pikachu card from the American Base Set published by Wizards of the Coast in 1999. It sold for $1,380.00.
While any card from the Pokémon Trading Card Game's original Base Set, Unlimited Variant or not, is sought after by collectors, this card is particularly valuable because it is one of two possible variants of the card. When this set was initially released, Pikachu could be found with red or yellow cheeks, with either color sporting a different rarity. The original card art sported a red-cheeked Pikachu and is considered the rarer version, with a frequency rate of 20%. The yellow-cheeked Pikachu is more common, making up the remaining 80%. While this card is a "Yellow Cheeks" variant, it's still a very rare card that is highly sought after by collectors.
Not only is this card a special find, but it is also in remarkably good condition, with a PSA rating of Gem Mint 10 which, according to the PSA Grading Scale, means the card is virtually perfect. In addition to being completely free of stains, marks or imperfections, Gem Mint 10 cards feature "four perfectly sharp corners, sharp focus and full original gloss."
The "Yellow Cheeks" variant of the Base Set Unlimited Pikachu card is no longer available for purchase on Heritage Auctions.
Sources: Heritage Auctions, PSA Grading Scale