Cheapest priced copy (Murders at Karlov Manor Commander): $0.49 at Card Kingdom, near mint, their price list as of .
Eye of Duskmantle 
Creature — Eye · 3/8 · Rare · Murders at Karlov Manor Commander · #337
Flying, lifelink
You may play lands and cast spells from among cards in your graveyard you've surveilled this turn. If you cast a spell this way, you pay life equal to its mana value rather than paying its mana cost.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
2 printings · $0.49 to $0.69 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Murders at Karlov Manor Commander | 27 | Rare | $0.49 | — |
| Murders at Karlov Manor Commander | 337 | Rare | $0.69 | — |
3 rulings from Wizards of the Coast
- 2 February 2024You may only cast spells this way by paying the appropriate amount of life. You may not pay their normal costs and may not pay any other alternative costs. You may still pay for additional costs, such as kicker costs. If the spell has mandatory additional costs, you must pay those.
- 2 February 2024If you cast a spell with {X} in its mana cost this way, the only legal choice for X is 0.
- 2 February 2024“Cards in your graveyard you’ve surveilled this turn” includes cards you put into your graveyard while surveilling. It does not include cards you saw while surveilling, left on top of your library, and then put into your graveyard later that turn by other means.