Cheapest priced copy (Jumpstart): $0.79 at Card Kingdom, near mint, their price list as of .
Cradle of Vitality 
Enchantment · Rare · Shards of Alara · #7
Whenever you gain life, you may pay {1}{W}. If you do, put a +1/+1 counter on target creature for each 1 life you gained.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
3 printings · $0.79 to $1.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Shards of Alara | 7 | Rare | $0.99 | $1.49 |
| Commander 2013 | 7 | Rare | $0.99 | — |
| Jumpstart | 98 | Rare | $0.79 | — |
3 rulings from Wizards of the Coast
- 1 October 2008You choose a target when the ability triggers. You don’t choose whether to pay {1}{W} until the ability resolves.
- 1 October 2008Cradle of Vitality triggers just once for each life-gaining event, whether it’s 1 life from Deathgreeter or 8 life from Soul’s Grace. You pay the cost just once, but the targeted creature will get a number of counters equal to the amount of life you gained.
- 1 February 2014If multiple creatures you control with lifelink deal damage simultaneously, each instance is a single life-gain event and the ability will trigger separately for each of them.