Cheapest priced copy (Edge of Eternities): $0.49 at Card Kingdom, near mint, their price list as of .
Rust Harvester 
Artifact Creature — Robot · 1/1 · Rare · Edge of Eternities · #159
Menace
{2}, {T}, Exile an artifact card from your graveyard: Put a +1/+1 counter on this creature, then it deals damage equal to its power to any target.
Legal inCommanderBrawlStandardPioneerModernLegacyVintage
Not legal inPauper
4 printings · $0.49 to $0.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Edge of Eternities | 159 | Rare | $0.49 | $0.49 |
| Edge of Eternities | 310 | Rare | $0.49 | $0.49 |
| Edge of Eternities Promos | 159p | Rare | $0.49 | $0.49 |
| Edge of Eternities Promos | 159s | Rare | — | $0.99 |
2 rulings from Wizards of the Coast
- 25 July 2025If Rust Harvester leaves the battlefield before its last ability resolves, it won’t have a +1/+1 counter put on it when the ability resolves. Use its power as it last existed on the battlefield to determine how much damage is dealt.
- 25 July 2025If the target is illegal as Rust Harvester’s last ability tries to resolve, it won’t resolve and none of its effects will happen. You won’t put a +1/+1 counter on Rust Harvester.