Cheapest priced copy (Battle for Zendikar): $0.49 at Card Kingdom, near mint, their price list as of .
Veteran Warleader 
Creature — Human Soldier Ally · */* · Rare · Battle for Zendikar · #221
Veteran Warleader's power and toughness are each equal to the number of creatures you control.
Tap another untapped Ally you control: This creature gains your choice of first strike, vigilance, or trample until end of turn.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
3 printings · $0.49 to $2.29 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Battle for Zendikar | 221 | Rare | $0.49 | $0.49 |
| Duel Decks: Zendikar vs. Eldrazi | 27 | Rare | $0.49 | — |
| Battle for Zendikar Promos | 221s | Rare | — | $2.29 |
4 rulings from Wizards of the Coast
- 25 August 2015Vigilance matters only as attackers are declared. Giving a creature vigilance after that point won't untap it, even if it's attacking.
- 25 August 2015To activate the last ability, you can tap any other untapped Ally you control, including one that hasn't been under your control since the beginning of your most recent turn. (Note that ability doesn't use the tap symbol.)
- 25 August 2015You choose which ability Veteran Warleader gains as the last ability resolves, not as you activate it.
- 25 August 2015The ability that defines Veteran Warleader's power and toughness works in all zones, not just the battlefield. If Veteran Warleader is on the battlefield, it will count itself.