Cheapest priced copy (Duskmourn: House of Horror): $0.35 at Card Kingdom, near mint, their price list as of .
Scorching Dragonfire 
Instant · Common · Duskmourn: House of Horror · #156
Scorching Dragonfire deals 3 damage to target creature or planeswalker. If that creature or planeswalker would die this turn, exile it instead.
Legal inCommanderBrawlStandardPioneerModernLegacyVintagePauper
5 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Duskmourn: House of Horror | 156 | Common | $0.35 | $0.49 |
| Throne of Eldraine | 139 | Common | $0.35 | $0.49 |
| Foundations | 545 | Common | $0.35 | — |
| Jumpstart 2022 | 596 | Common | $0.35 | — |
| Core Set 2021 | 158 | Common | $0.35 | $0.49 |
3 rulings from Wizards of the Coast
- 4 October 2019Scorching Dragonfire's replacement effect will exile the target creature or planeswalker if it would die this turn for any reason, not just due to lethal damage. It applies to the target creature or planeswalker even if Scorching Dragonfire deals no damage to it (most likely due to a prevention effect).
- 23 June 2020Scorching Dragonfire's replacement effect will exile the target creature or planeswalker if it would die this turn for any reason, not just due to lethal damage.
- 20 September 2024Scorching Dragonfire's replacement effect will exile the target creature or planeswalker if it would die this turn for any reason, not just due to lethal damage.