Cheapest priced copy (The List): $0.35 at Card Kingdom, near mint, their price list as of .
Sigil of the New Dawn 
Enchantment · Uncommon · Ultimate Masters · #35
Whenever a creature is put into your graveyard from the battlefield, you may pay {1}{W}. If you do, return that card to your hand.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
3 printings · $0.35 to $3.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Onslaught | 55 | Rare | $0.49 | $3.49 |
| The List | UMA-35 | Uncommon | $0.35 | — |
| Ultimate Masters | 35 | Uncommon | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 7 December 2018Sigil of the New Dawn's ability triggers if a creature you own dies under another player's control.
- 7 December 2018If a creature you own dies at the same time that Sigil of the New Dawn leaves the battlefield, Sigil of the New Dawn's ability triggers for that creature.