Cheapest priced copy (Jumpstart 2022): $0.35 at Card Kingdom, near mint, their price list as of .
Berg Strider 
Snow Creature — Giant Wizard · 4/4 · Common · Kaldheim · #47
When this creature enters, tap target artifact or creature an opponent controls. If {S} was spent to cast this spell, that permanent doesn't untap during its controller's next untap step. ({S} is mana from a snow source.)
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
3 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Jumpstart 2022 | 277 | Common | $0.35 | — |
| Kaldheim | 47 | Common | $0.35 | $0.49 |
| The List | KHM-47 | Common | $0.35 | — |
9 rulings from Wizards of the Coast
- 5 February 2021The enters-the-battlefield ability can target an artifact or creature an opponent controls that’s already tapped. If snow mana was spent to cast Berg Strider, the target won’t untap during its controller’s next untap step.
- 5 February 2021Similarly, if an effect copies the creature spell that becomes Berg Strider, no mana was spent to cast the copy. The target won’t be stopped from untapping during its controller’s next untap step.
- 5 February 2021If Berg Strider enters the battlefield without being cast, no mana was spent to cast it. The enters-the-battlefield ability may still tap the target, but that permanent won’t be stopped from untapping during its controller’s next untap step.
- 5 February 2021Some cards have additional effects for each {S} spent to cast them. You can cast these spells even if you don’t spend any snow mana to cast them; their additional effects simply won’t do anything.
- 5 February 2021The {S} symbol is a generic mana symbol. It represents a cost that can be paid by one mana that was produced by a snow source. That mana can be any color or colorless.
- 5 February 2021Snow is a supertype, not a card type. It has no rules meaning or function by itself, but spells and abilities may refer to it.
- 5 February 2021The Kaldheim set doesn’t have any cards with mana costs that include {S}, but some previous sets do. If an effect says such a spell costs {1} less to cast, that reduction doesn’t apply to any {S} costs. This is also true for activated abilities that include {S} in their activation costs and effects that reduce those costs.
- 5 February 2021Snow isn’t a type of mana. If an effect says you may spend mana as though it were any type, you can’t pay for {S} using mana that wasn’t produced by a snow source.
- 5 February 2021Spending more than one snow mana to cast Berg Strider won’t cause the artifact or creature to remain tapped for additional turns.