Buying from notable auction houses (not ebay) and from reputable sellers is still the best thing to do for these types of cards
There are four basic levels of rarity: Common, Uncommon, Rare, and Promo
1 Delina, Wild Mage
In October 2022, a PSA 10 graded 2002 1st Edition Mysterious Mountains Crystal Charizard card was sold at auction at PWCC for $40,800 , making it the most expensive e-Card in the series
New design In December 2001, the Base Expansion Pack was released in Japan
And maybe some is even printed overseas (quiet possible speciality cards like Trophy cards are printed by MediaFactory in Japan) thundermoo January 8, 2020, 9:45pm 5 When Cartamundi purchased USPC it was mentioned in a couple articles that they print for Pokemon binx345 January 8, 2020, 10:23pm 6 At one point some were printed around Raleigh, NC but I do not know if they still are