Cheapest priced copy (Gatecrash): $0.35 at Card Kingdom, near mint, their price list as of .
Gruul Charm 
Instant · Uncommon · RNA Guild Kit · #92
Choose one —
• Creatures without flying can't block this turn.
• Gain control of all permanents you own.
• Gruul Charm deals 3 damage to each creature with flying.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.35 to $1.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| RNA Guild Kit | 92 | Uncommon | $0.99 | — |
| Gatecrash | 169 | Uncommon | $0.35 | $1.49 |
3 rulings from Wizards of the Coast
- 24 January 2013If you choose the first mode, no creature without flying will be able to block that turn, including creatures that lose flying and creatures without flying that enter after Gruul Charm resolves.
- 24 January 2013A token is owned by the player under whose control it entered.
- 24 January 2013If you choose the second mode, Gruul Charm's effect will override any other control-changing effects on those permanents.