Cheapest priced copy (Modern Horizons): $0.35 at Card Kingdom, near mint, their price list as of .
First-Sphere Gargantua 
Creature — Phyrexian Horror · 5/4 · Common · March of the Machine Commander · #248
When this creature enters, you draw a card and you lose 1 life.
Unearth {2}{B} ({2}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
3 printings · $0.35 to $0.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Modern Horizons | 91 | Common | $0.35 | $0.79 |
| March of the Machine Commander | 248 | Common | $0.35 | — |
| The List | MH1-91 | Common | $0.35 | — |
2 rulings from Wizards of the Coast
- 14 June 2019If a creature returned to the battlefield by the unearth ability would leave it for any reason, it's exiled instead—unless the spell or ability that's causing the creature to leave the battlefield is actually trying to exile it. In that case, the spell or ability succeeds at exiling the creature. If the spell or ability later returns the creature card to the battlefield (as Astral Drift might, for example), the creature card will return as a new object with no relation to its previous existence. The unearth effect will no longer apply to it.
- 14 June 2019Activating a creature card's unearth ability isn't the same as casting the creature card. The unearth ability is put on the stack, but the creature card is not. Spells and abilities that interact with activated abilities (such as Stifle) will interact with unearth, but spells and abilities that interact with spells (such as Cancel) will not.