Cheapest priced copy (Modern Horizons 3): $0.49 at Card Kingdom, near mint, their price list as of .
Eviscerator's Insight 
Instant · Common · Modern Horizons 3 · #93
As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards.
Flashback {4}{B} (You may cast this card from your graveyard for its flashback cost and any additional costs. Then exile it.)
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
1 printing · $0.49 to $0.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Modern Horizons 3 | 93 | Common | $0.49 | $0.79 |
5 rulings from Wizards of the Coast
- 7 June 2024To determine the total cost of a spell, start with the mana cost or alternative cost (such as a flashback cost) you're paying, add any cost increases, then apply any cost reductions. The mana value of the spell is determined only by its mana cost, no matter what the total cost to cast the spell was.
- 7 June 2024You can cast a spell using flashback even if it was somehow put into your graveyard without having been cast.
- 7 June 2024A spell cast using flashback will always be exiled afterward, whether it resolves, is countered, or leaves the stack in some other way.
- 7 June 2024If a card with flashback is put into your graveyard during your turn, you can cast it if it's legal to do so before any other player can take any actions.
- 7 June 2024"Flashback [cost]" means "You may cast this card from your graveyard by paying [cost] rather than paying its mana cost" and "If the flashback cost was paid, exile this card instead of putting it anywhere else any time it would leave the stack."