Its specific numbering system that apparently follows the National Pokdex scheme (putting Bulbasaur as #001 and Mew as #151)
Right now the most expensive Digimon card in our price guide is BeelStarmon X Antibody Textured, at a market price of $1,449.50
Many valuable Pokmon cards originate in Japanese-only releases or have alternate art versions not available in English
Prosper, Tome-Bound is no exception, and will fit right in amongst these other Rakdos commanders
Cards with known print quality issues are often strong targets because a high-grade copy is legitimately rare and collectors know it
Still, for both the Elderhall and Stronghold, I suspect the lost tempo of playing a tapland in aggressive, snowballing synergy decks combined with the decidedly low-impact activated abilities will relegate these to Limited card status even if a counters or elf strategy does become popular