Best starting point: Pokemon 151 (Scarlet & Violet era) or Base Set Unlimited singles
It can be tricky to tell whether a Pokmon card is fake
The markup on the Vivi Ornitier decklist I looked up came from a TCGplayer market value of about $75 before shipping, to a cost of $190
This is one of the most debated topics by Plasma players when they compare their builds
However, if all else fails, the eBay seller is selling other single cards from as little as $8 with a $12 shipping fee, so well be getting no free postage on these transactions, unfortunately
They are all alternate art versions of cards that already feature within the standard 204 card sets, with the difference being the artwork and rarity symbol, which is unique to Enchanted cards