Cheapest priced copy (Theros Beyond Death Promos): $0.49 at Card Kingdom, foil, near mint, their price list as of .
Purphoros's Intervention 
Sorcery · Rare · Theros Beyond Death · #320
Choose one —
• Create an X/1 red Elemental creature token with trample and haste. Sacrifice it at the beginning of the next end step.
• Purphoros's Intervention deals twice X damage to target creature or planeswalker.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
4 printings · $0.49 to $0.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Theros Beyond Death Promos | 151p | Rare | $0.59 | $0.79 |
| Theros Beyond Death Promos | 151s | Rare | — | $0.49 |
| Theros Beyond Death | 151 | Rare | $0.49 | $0.49 |
| Theros Beyond Death | 320 | Rare | $0.49 | $0.79 |
One ruling from Wizards of the Coast
- 24 January 2020The second mode of Purphoros’s Intervention has it deal damage to the target equal to twice X. It doesn’t deal X damage then deal X damage again.