Cheapest priced copy (Commander 2016): $0.99 at Card Kingdom, near mint, their price list as of .
Primeval Protector 
Creature — Avatar · 10/10 · Rare · Neon Dynasty Commander · #124
This spell costs {1} less to cast for each creature your opponents control.
When this creature enters, put a +1/+1 counter on each other creature you control.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
2 printings · $0.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander 2016 | 23 | Rare | $0.99 | — |
| Neon Dynasty Commander | 124 | Rare | $0.99 | — |
2 rulings from Wizards of the Coast
- 8 November 2016Primeval Protector's ability can't reduce its cost below {G}.
- 8 November 2016Once a player has announced that they are casting Primeval Protector, no player may take actions to try to change the number of creatures your opponents control in order to increase its cost.