Cheapest priced copy (Murders at Karlov Manor): $0.35 at Card Kingdom, near mint, their price list as of .
Crimestopper Sprite 
Creature — Faerie Detective · 2/2 · Common · Murders at Karlov Manor · #49
As an additional cost to cast this spell, you may collect evidence 6. (Exile cards with total mana value 6 or greater from your graveyard.)
Flying
When this creature enters, tap target creature. If evidence was collected, put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Legal inCommanderBrawlStandardPioneerModernLegacyVintagePauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Murders at Karlov Manor | 49 | Common | $0.35 | $0.49 |
3 rulings from Wizards of the Coast
- 2 February 2024You may target a creature that is already tapped with Crimestopper Sprite's last ability. If the target creature is already tapped as the ability resolves and evidence was collected, you will still put a stun counter on it.
- 2 February 2024If you can't exile enough cards to meet or exceed the required mana value, you can't choose to collect evidence at all.
- 2 February 2024Once you've announced that you're casting a spell, players can't take actions until you've finished doing so. Notably, opponents can't try to remove cards from your graveyard to stop you from collecting evidence.