Legendary Land Color tag templates(None) Kazandu Mammoth Landfall Whenever a land you control enters, this creature gets +2/+2 until end of turn
Officially licensed Deck Box card storage for Magic: The Gathering Tarkir Dragonstorm
Of course, it doesn't guarantee the immense popularity of the card, so it's hard to say in what direction that price will go
Add to this the fact that it was a card given away at a convention not specializing in TCGs, and few have kept it in perfect condition (potential CCC 10)
Simple, effective, versatile removal for Sapphire
With access to counterspells, redirects and cheap reanimator, they need dealing with to stop their inevitable domination