Cheapest priced copy (Marvel Super Heroes Commander): $5.99 at Card Kingdom, near mint, their price list as of .
Black Panther's Claws 
Hammer of Nazahn
Legendary Artifact — Equipment · Rare · Marvel Super Heroes Commander · #427
Whenever Hammer of Nazahn or another Equipment you control enters, you may attach that Equipment to target creature you control.
Equipped creature gets +2/+0 and has indestructible.
Equip {4}
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
7 printings · $5.99 to $15.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Double Masters | 260 | Rare | $12.99 | $14.99 |
| Commander 2017 | 51 | Rare | $11.99 | — |
| Commander Masters | 388 | Rare | $11.99 | $15.99 |
| Commander Masters | 606 | Rare | — | — |
| Marvel Super Heroes Commander (Black Panther's Claws) | 286 | Rare | $5.99 | $6.99 |
| Marvel Super Heroes Commander (Black Panther's Claws) | 427 | Rare | $8.49 | — |
| Secret Lair Drop (Piko Piko Hammer) | 2098 | Rare | $9.99 | $12.99 |
2 rulings from Wizards of the Coast
- 7 August 2020If Hammer of Nazahn enters the battlefield at the same time as other Equipment you control, its ability will trigger for each of those Equipment.
- 7 August 2020Because damage remains marked on a creature until the damage is removed as the turn ends, nonlethal damage dealt to the equipped creature may become lethal if you attach Hammer of Nazahn to a different creature during that turn.