Cheapest priced copy (Mirrodin): $5.49 at Card Kingdom, near mint, their price list as of .
Nightmare Lash 
Artifact — Equipment · Rare · Mirrodin · #219
Equipped creature gets +1/+1 for each Swamp you control.
Equip—Pay 3 life. (Pay 3 life: Attach to target creature you control. Equip only as a sorcery.)
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
1 printing · $5.49 to $19.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Mirrodin | 219 | Rare | $5.49 | $19.99 |