Cheapest priced copy (Murders at Karlov Manor): $0.35 at Card Kingdom, near mint, their price list as of .
Surveillance Monitor 
Creature — Vedalken Detective · 3/3 · Uncommon · Murders at Karlov Manor · #73
When this creature enters, you may collect evidence 4. (Exile cards with total mana value 4 or greater from your graveyard.)
Whenever you collect evidence, create a 1/1 colorless Thopter artifact creature token with flying.
Legal inCommanderBrawlStandardPioneerModernLegacyVintage
Not legal inPauper
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Murders at Karlov Manor | 73 | Uncommon | $0.35 | $0.49 |
| Murders at Karlov Manor | 73† | Uncommon | — | — |
3 rulings from Wizards of the Coast
- 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.
- 2 February 2024Surveillance Monitor's last ability triggers whenever you collect evidence for any reason, not just when you collect evidence with its first ability.