Cheapest priced copy (Avatar: The Last Airbender Eternal): $0.35 at Card Kingdom, near mint, their price list as of .
Roku's Mastery 
Instant · Uncommon · Avatar: The Last Airbender Eternal · #243
Roku's Mastery deals X damage to target creature. If X is 4 or more, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Avatar: The Last Airbender Eternal | 243 | Uncommon | $0.35 | $0.49 |