Cheapest priced copy (Time Spiral Remastered): $1.79 at Card Kingdom, near mint, their price list as of .
Slaughter Pact 
Instant · Rare · Future Sight · #78
Destroy target nonblack creature.
At the beginning of your next upkeep, pay {2}{B}. If you don't, you lose the game.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
4 printings · $1.79 to $49.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Future Sight | 78 | Rare | $3.49 | $44.99 |
| Modern Masters | 97 | Rare | $2.79 | $8.99 |
| Amonkhet Invocations | 44 | Special | — | $49.99 |
| Time Spiral Remastered | 138 | Rare | $1.79 | $6.99 |
3 rulings from Wizards of the Coast
- 7 June 2013Although originally printed with a characteristic-defining ability that defined its color, this card now has a color indicator. This color indicator can't be affected by text-changing effects (such as the one created by Crystal Spray), although color-changing effects can still overwrite it.
- 19 March 2021If Slaughter Pact is countered or otherwise doesn't resolve (perhaps because its target became illegal), the delayed triggered ability that threatens you with a game loss won't trigger at the beginning of your next upkeep.
- 19 March 2021If Slaughter Pact resolves with a legal target but the target is not destroyed (perhaps because it has indestructible or regenerated), the delayed triggered ability will still trigger at the beginning of your next upkeep and you will have to pay the cost or lose the game.