Cheapest priced copy (Kaldheim Commander): $0.49 at Card Kingdom, near mint, their price list as of .
Serpent's Soul-Jar 
Artifact · Rare · Kaldheim Commander · #11
Whenever an Elf you control dies, exile it.
{T}, Pay 2 life: Until end of turn, you may cast a creature spell from among cards exiled with this artifact.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Kaldheim Commander | 11 | Rare | $0.49 | — |
2 rulings from Wizards of the Coast
- 5 February 2021Players can respond to the triggered ability that exiles the card from your graveyard by removing it in some other way. If the card leaves the graveyard before the ability of Serpent's Soul-Jar exiles it, Serpent's Soul-Jar won't let you cast it.
- 5 February 2021The activated ability doesn't change when you can cast the creature spell. In most cases, this means during your main phase while the stack is empty, although flash may change this.