Cheapest priced copy (Commander Legends): $0.35 at Card Kingdom, near mint, their price list as of .
Pennon Blade 
Artifact — Equipment · Uncommon · Rise of the Eldrazi · #221
Equipped creature gets +1/+1 for each creature you control.
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
2 printings · $0.35 to $0.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander Legends | 329 | Uncommon | $0.35 | $0.49 |
| Rise of the Eldrazi | 221 | Uncommon | $0.35 | $0.79 |
One ruling from Wizards of the Coast
- 15 June 2010As long as you control Pennon Blade, its ability constantly counts the number of creatures you control. It doesn't matter who controls the creature it's equipping (in case an opponent somehow manages to take control of that creature). If you control the creature it's equipping, the bonus will include that creature too.