Cheapest priced copy (Ravnica Allegiance): $0.99 at Card Kingdom, near mint, their price list as of .
Emergency Powers 
Instant · Mythic · Ravnica Allegiance · #169
Each player shuffles their hand and graveyard into their library, then draws seven cards. Exile Emergency Powers.
Addendum — If you cast this spell during your main phase, you may put a permanent card with mana value 7 or less from your hand onto the battlefield.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.99 to $2.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Ravnica Allegiance Promos | 169s | Mythic | — | $2.49 |
| Ravnica Allegiance | 169 | Mythic | $0.99 | $2.99 |
3 rulings from Wizards of the Coast
- 25 January 2019If a card in your hand has {X} in its mana cost, X is considered to be 0.
- 12 January 2024Addendum abilities of instant spells apply while the spell is resolving, not immediately after casting it. If the spell is countered, you don't get the addendum bonus.
- 12 January 2024If an effect copies a spell with an addendum ability while it's on the stack, the copy wasn't cast at all, so you won't get the addendum bonus.