Cheapest priced copy (Wilds of Eldraine Commander): $1.29 at Card Kingdom, near mint, their price list as of .
Korvold, Gleeful Glutton 
Legendary Creature — Dragon Noble · 4/4 · Mythic · Wilds of Eldraine Commander · #38
This spell costs {1} less to cast for each card type among permanents you've sacrificed this turn.
Flying, trample, haste
Whenever Korvold deals combat damage to a player, put X +1/+1 counters on Korvold and draw X cards, where X is the number of permanent types among cards in your graveyard.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
2 printings · $1.29 to $1.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Wilds of Eldraine Commander | 26 | Mythic | $1.49 | $1.49 |
| Wilds of Eldraine Commander | 38 | Mythic | $1.29 | $1.99 |
3 rulings from Wizards of the Coast
- 1 September 2023The cost-reduction ability of Korvold, Gleeful Glutton doesn't change its mana cost or mana value, only the total cost you pay. Specifically, the mana value of Korvold, Gleeful Glutton is always 8.
- 1 September 2023Korvold's cost-reduction ability doesn't affect the colored mana in its mana cost. It can't reduce its cost to less than {B}{R}{G}.
- 1 September 2023The permanent types are artifact, battle, creature, enchantment, land, and planeswalker. Things like "legendary" or "snow" are supertypes, not types. "Token" is not a type.