Maybe this is why I'm not a game developer, but I can't imagine how anyone would get 10-12 pages of interesting, worthwhile content out of, for example, the Euryale, Gem, Stars, or Fool cards. Cards like Flames, Knight, and Donjon could provide some good content, but jeez, it'd be a stretch for some of the rest. And seriously, how many games ever include the Deck anyway? Bigby's is niche - an entire book devoted to one magic item (that most DMs won't allow remotely near their campaigns anyway) is the nichiest niche in nichetown.