Cheapest priced copy (Commander Masters): $32.99 at Card Kingdom, near mint, their price list as of .
Finale of Devastation 
Sorcery · Mythic · War of the Spark · #160
Search your library and/or graveyard for a creature card with mana value X or less and put it onto the battlefield. If you search your library this way, shuffle. If X is 10 or more, creatures you control get +X/+X and gain haste until end of turn.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
8 printings · $32.99 to $109.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander Masters | 289 | Mythic | $32.99 | $59.99 |
| Commander Masters | 559 | Mythic | — | — |
| Commander Masters | 700 | Mythic | $44.99 | $109.99 |
| War of the Spark Promos | 160p | Mythic | $39.99 | $99.99 |
| War of the Spark Promos | 160s | Mythic | — | $99.99 |
| Secret Lair Drop | 2438 | Mythic | — | $49.99 |
| Secret Lair Drop | 2680 | Mythic | $37.99 | $34.99 |
| War of the Spark | 160 | Mythic | $34.99 | $54.99 |
4 rulings from Wizards of the Coast
- 3 May 2019No player may take action between the time you reveal which creature card you'll put onto the battlefield and the time it gets +X/+X and haste if X is 10 or more. Any abilities that trigger as it enters the battlefield will be put onto the stack after your creatures get +X/+X and haste.
- 3 May 2019If you don't find a creature card with mana value X or less, creatures you control still get +X/+X and gain haste if X is 10 or more.
- 3 May 2019If X is 10 or more, the creature card you just put onto the battlefield will get +X/+X and haste.
- 3 May 2019If a creature card in your library or graveyard has {X} in its mana cost, X is considered to be 0.