Cheapest priced copy (Tenth Edition): $8.99 at Card Kingdom, near mint, their price list as of .
Mortal Combat 
Enchantment · Rare · Tenth Edition · #160
At the beginning of your upkeep, if twenty or more creature cards are in your graveyard, you win the game.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
2 printings · $8.99 to $44.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Tenth Edition | 160 | Rare | $8.99 | $16.99 |
| Torment | 71 | Rare | $9.99 | $44.99 |
2 rulings from Wizards of the Coast
- 15 July 2007If you don’t have twenty or more creature cards in your graveyard by the time your upkeep starts, the ability won’t trigger that turn.
- 15 July 2007Mortal Combat’s ability has an “intervening ‘if’ clause,” so the condition is checked again when the triggered ability resolves. If you don’t still have twenty creature cards in your graveyard, the ability does nothing.