they are sourced from compromised devices and are frequently used for fraud, meaning their IPs are on every retailer's blocklist before you even try them
EX Crystal Guardians Castaway Perhaps the best Supporter card printed in the Pokmon TCG

King T'Challa 3.6%inclusion 42 decks 1.17K decks The Sentry, Golden Guardian 2.5%inclusion 30 decks 1.18K decks Jennifer Walters 2.6%inclusion 20 decks 768 decks Storm, Windrider 2.7%inclusion 15 decks 563 decks Willie Lumpkin, Postman 1.8%inclusion 12 decks 669 decks Top Commanders Zur the Enchanter 38%inclusion 6.17K decks 16.2K decks Grand Arbiter Augustin IV 32%inclusion 4.32K decks 13.3K decks Hope Estheim 24%inclusion 4.05K decks 16.6K decks Sythis, Harvest's Hand 24%inclusion 3.37K decks 13.8K decks Ketramose, the New Dawn 22%inclusion 2.17K decks 9.86K decks Ellivere of the Wild Court 21%inclusion 1.63K decks 7.88K decks Lavinia, Azorius Renegade 42%inclusion 1.40K decks 3.32K decks Winota, Joiner of Forces 7.2%inclusion 959 decks 13.4K decks Heliod, Sun-Crowned 18%inclusion 923 decks 5.09K decks Oloro, Ageless Ascetic 3.9%inclusion 841 decks 21.3K decks Zedruu the Greathearted 6.8%inclusion 812 decks 12K decks Giada, Font of Hope 2.4%inclusion 809 decks 33K decks Alela, Artful Provocateur 4.8%inclusion 781 decks 16.1K decks Shorikai, Genesis Engine 3.8%inclusion 780 decks 20.4K decks Tuvasa the Sunlit 8.8%inclusion 677 decks 7.71K decks Myrel, Shield of Argive 7.2%inclusion 613 decks 8.48K decks Kwain, Itinerant Meddler 8.8%inclusion 598 decks 6.79K decks Ezio Auditore da Firenze 3.2%inclusion 589 decks 18.4K decks Sen Triplets 7.6%inclusion 584 decks 7.66K decks The War Doctor // Clara Oswald 43%inclusion 556 decks 1.28K decks Light-Paws, Emperor's Voice 4.5%inclusion 531 decks 11.9K decks Derevi, Empyrial Tactician 4.1%inclusion 490 decks 11.8K decks Ms

2 Character Bases
A combination of power in the game, rarity and popularity as a Pokemon are what has driven the price of Rayquaza GX rainbow rare
Even combo plays little pure card draw any more, it may well have the odd symmetrical draw seven effect but these are usually for the ability to get back spent combo cards should the game go on a little longer than desired