Cheapest priced copy (Future Sight): $0.35 at Card Kingdom, near mint, their price list as of .
Grinning Ignus 
Creature — Elemental · 2/2 · Uncommon · Modern Masters · #118
{R}, Return this creature to its owner's hand: Add {C}{C}{R}. Activate only as a sorcery.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
4 printings · $0.35 to $3.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Future Sight | 116 | Common | $0.35 | $3.99 |
| Modern Masters | 118 | Uncommon | $0.39 | $0.99 |
| Strixhaven: School of Mages | 104 | Uncommon | $0.35 | $0.49 |
| Time Spiral Remastered | 168 | Common | $0.35 | $0.49 |
4 rulings from Wizards of the Coast
- 19 March 2021Although Grinning Ignus's ability has a timing restriction, it's still a mana ability. It doesn't use the stack and it can't be responded to.
- 19 March 2021If you cast Grinning Ignus during your main phase, it will enter the battlefield and you'll receive priority. If no abilities trigger because of this, you can activate its ability immediately, before any other player has a chance to remove it from the battlefield.
- 16 April 2021If you cast this as normal during your main phase, it will enter the battlefield and you'll receive priority. If no abilities trigger because of this, you can activate its ability immediately, before any other player has a chance to remove it from the battlefield.
- 16 April 2021Although Grinning Ignus's ability has a timing restriction, it's still a mana ability. It doesn't use the stack and it can't be responded to.