The lucky chap who found the card, one Brook Trafton, confirmed that he paid a total of $2 million for the blingy piece
In the late game, just make some extra life as you have more mana than you can harnessa lot of decks have acceleration for mana and then just sit on 10 or 12 mana for turn after turn with not much to do with it, and this gives you an option
Ancient Silver Dragon Anvil of Bogardan Body of Knowledge Choice of Fortunes Chronatog Avatar Curiosity Crafter Decanter of Endless Water Enter the Infinite Finale of Revelation Folio of Fancies Graceful Adept Kruphix, God of Horizons Library of Leng Marina Vendrell's Grimoire Mine, Mine, Mine
Such mischief
To determine the total cost of a spell, start with the mana cost or alternative cost you're paying (such as an escape cost), add any cost increases, then apply any cost reductions