Cheapest priced copy (Shards of Alara): $0.35 at Card Kingdom, near mint, their price list as of .
Gustrider Exuberant 
Creature — Human Wizard · 1/2 · Common · Shards of Alara · #13
Flying
Sacrifice this creature: Creatures you control with power 5 or greater gain flying until end of turn.
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Shards of Alara | 13 | Common | $0.35 | $0.49 |
One ruling from Wizards of the Coast
- 1 October 2008The ability doesn’t target, so it checks the creatures’ powers only once: when the ability resolves. Once the ability resolves, it will continue to apply to the affected creatures no matter what their powers may become later in the turn.