Cheapest priced copy (Foundations Jumpstart): $0.35 at Card Kingdom, near mint, their price list as of .
Skyclave Pick-Axe 
Artifact — Equipment · Uncommon · Foundations Jumpstart · #712
When this Equipment enters, attach it to target creature you control.
Landfall — Whenever a land you control enters, equipped creature gets +2/+2 until end of turn.
Equip {2}{G} ({2}{G}: Attach to target creature you control. Equip only as a sorcery.)
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
3 printings · $0.35 to $0.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Foundations Jumpstart | 712 | Uncommon | $0.35 | — |
| Zendikar Rising | 204 | Uncommon | $0.35 | $0.49 |
| Zendikar Rising | 309 | Uncommon | $0.35 | $0.79 |
7 rulings from Wizards of the Coast
- 25 September 2020If there's no equipped creature as Skyclave Pick-Axe's landfall ability resolves, no creature gets +2/+2.
- 25 September 2020Attaching an Equipment with its enters-the-battlefield triggered ability isn't the same as using its equip ability. You don't pay mana for the attachment, and if the Equipment enters at a time you couldn't cast a sorcery, you can still attach it to a creature you control.
- 25 September 2020The bonus from Skyclave Pick-Axe's landfall ability applies to the creature it's attached to at the time the ability resolves. That bonus doesn't apply to a new creature if Skyclave Pick-Axe becomes attached to a new creature.
- 25 September 2020If the target creature becomes an illegal target, the Equipment remains on the battlefield unattached.
- 8 November 2024Whenever a land you control enters, each landfall ability of the permanents you control will trigger. You can put them on the stack in any order. The last ability you put on the stack will be the first one to resolve (As a result, you can have those abilities resolve in the order of your choosing.).
- 8 November 2024A landfall ability doesn't trigger if a permanent already on the battlefield becomes a land.
- 8 November 2024A landfall ability triggers whenever a land you control enters for any reason. It triggers whenever you play a land, as well as whenever a spell or ability puts a land onto the battlefield under your control.