Cheapest priced copy (Kaldheim): $0.49 at Card Kingdom, near mint, their price list as of .
Surtland Flinger 
Creature — Giant Berserker · 4/6 · Rare · Kaldheim · #377
Whenever this creature attacks, you may sacrifice another creature. When you do, this creature deals damage equal to the sacrificed creature's power to any target. If the sacrificed creature was a Giant, this creature deals twice that much damage instead.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Kaldheim | 377 | Rare | $0.49 | — |
2 rulings from Wizards of the Coast
- 5 February 2021Surtland Flinger’s triggered ability goes on the stack without a target. While that ability is resolving, you may sacrifice another creature. When you do, the reflexive triggered ability triggers and you pick a target to be dealt damage. This is different from effects that say “If you do” in that players may take actions after you’ve sacrificed the creature but before damage is dealt.
- 5 February 2021Use the power of the creature as it was sacrificed to determine how much damage is dealt. Damage will be dealt before blockers are declared.