mtg cumulative upkeep cards Halls of Mist [Ice Age] then sacrifice it unless you pay its upkeep cost for each age counter on it.) Wave of Terror - LaughingDragonMTG

South Wind Avatar Your creatures will inevitably die over the course of a game, and South Wind Avatar keeps your life total far from a finish line

Even if you dont have a ton of ways to give your opponents creatures Flying, Storm makes your own fliers extremely difficult to block

attaching the effect to a creature that needs to survive a turn cycle and restricting the recursion to creatures makes the squirrel much less of a threat, but its still a formidable draw engine

From Belle to Beast Tragic Hero, which if undamaged in battle, will let you draw an additional card and if he has been damaged, you can add four strength points back to his total

New Phyrexia brought Karn Liberated, which was the first colorless planeswalker, requiring only generic mana to cast

I'm not sure if either of these cards have been sold before (certainly not recently), so it's impossible to place an accurate dollar figure on these unique pieces of history