Cheapest priced copy (Urza's Saga): $39.99 at Card Kingdom, near mint, their price list as of .
Lifeline 
Artifact · Rare · Urza's Saga · #299
Whenever a creature dies, if another creature is on the battlefield, return the first card to the battlefield under its owner's control at the beginning of the next end step.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $39.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Urza's Saga | 299 | Rare | $39.99 | — |
5 rulings from Wizards of the Coast
- 4 October 2004It works for all players and has errata to remove the “your graveyard” text.
- 4 October 2004It fails to bring the creature back if the creature is not still in the graveyard at the end of turn.
- 4 October 2004The creature comes back even if Lifeline leaves the battlefield after triggering, but before it resolves.
- 4 October 2004If multiple creatures are coming back, they come back one at a time, not all at once. This is because Lifeline triggered once for each creature and set up a separate “at end of turn” effect for each.
- 1 March 2010If more than one creature is on the battlefield and all the creatures on the battlefield go to the graveyard at once, then none of them are returned at end of turn. This is because Lifeline’s ability has an intervening-if clause, which means that there must be at least one creature on the battlefield at the time the ability resolves.