The most profitable Pokmon booster packs are packs that can no longer be bought, such as the 1st Edition Base Set
Like most Pokmon cards, the value of Rayquaza C LV.X depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Supreme Victors)
The difference between a grade 9 and a grade 10 can be tens of thousands of dollars, so a beat-up Base Set card from your attic isn't likely to be a winning lottery ticket
(See why hexproof is so polarizing?) Hexproof is a variation on an ability called shroud, which prevents creatures from being the target of any spell or ability, including yours
As a note, being part of the Dracula series didn't exclude a card from getting an extended-art version with the Innistrad: Crimson Vow art
Jared Mast, a veteran Pokmon card collector and consignment manager at auction house Goldin Auctions, told Dicebreaker that the first-edition holographic Chansey card released in 1999 had become extremely difficult to find in perfect condition - designated as Gem-Mint 10 by leading card grader PSA - as the result of numerous playground swaps that scuffed and scratched the shiny card