Cheapest priced copy (Invasion): $2.29 at Card Kingdom, near mint, their price list as of .
Crusading Knight 
Creature — Human Knight · 2/2 · Rare · Invasion · #12
Protection from black
This creature gets +1/+1 for each Swamp your opponents control.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $2.29 to $32.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Invasion | 12 | Rare | $2.29 | $32.99 |
One ruling from Wizards of the Coast
- 4 October 2004It counts all opponents' swamps.