Cheapest priced copy (Murders at Karlov Manor Commander): $0.59 at Card Kingdom, near mint, their price list as of .
Knowledge Is Power 
Enchantment · Rare · Murders at Karlov Manor Commander · #42
Creatures you control get +X/+X, where X is the number of cards you've drawn this turn.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
2 printings · $0.59 to $1.29 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Murders at Karlov Manor Commander | 42 | Rare | $0.59 | — |
| Murders at Karlov Manor Commander | 352 | Rare | $1.29 | — |