Cheapest priced copy (Jumpstart 2022): $0.35 at Card Kingdom, near mint, their price list as of .
Hooting Mandrills 
Creature — Ape · 4/4 · Common · Ultimate Masters · #170
Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Trample
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
4 printings · $0.35 to $0.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Jumpstart 2022 | 671 | Common | $0.35 | — |
| Khans of Tarkir | 137 | Common | $0.35 | $0.79 |
| The List | KTK-137 | Common | $0.35 | — |
| Ultimate Masters | 170 | Common | $0.35 | $0.49 |
3 rulings from Wizards of the Coast
- 19 March 2021Because delve isn't an alternative cost, it can be used in conjunction with alternative costs, such as flashback. It can also be used to pay for additional costs that include generic mana.
- 19 March 2021You can exile cards to pay only for generic mana, and you can't exile more cards than the generic mana requirement of a spell with delve. For example, you can't exile more than seven cards from your graveyard to cast Treasure Cruise unless an effect has increased its cost.
- 19 March 2021Delve doesn't change a spell's mana cost or mana value. For example, Treasure Cruise's mana value is 8 even if you exiled three cards to cast it.