While popularity and visuals play a role in this card's pricing, rarity also plays a role, as this card is incredibly difficult to find in good condition
Others focused entirely on countering it, but, either way, Zoroark came to dictate the game
Secret Rares, full arts, and alternate arts from special sets often hold the highest value
From memory Shadowspear was around five USD the first few weeks after THB released Because of its relevance in the Theros story arc, I think were mainly going to see it getting reprinted in supplemental sets or universes beyond sets because reprinting it in Amonkhet or Lorwyn would make little sense
Juju Bubble Juju Bubble is notoriously bad, and its also infamously common in older collections