Cheapest priced copy (Dark Ascension): $0.35 at Card Kingdom, near mint, their price list as of .
Gravepurge 
Instant · Common · Dragons of Tarkir · #104
Put any number of target creature cards from your graveyard on top of your library.
Draw a card.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
3 printings · $0.35 to $1.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Dark Ascension | 65 | Common | $0.35 | $1.99 |
| Dragons of Tarkir | 104 | Common | $0.35 | $1.49 |
| The List | DTK-104 | Common | $0.35 | — |
4 rulings from Wizards of the Coast
- 22 January 2011You can cast Gravepurge with zero targets. If you do, you’ll draw a card as the spell resolves.
- 22 January 2011If you cast Gravepurge with at least one target and all of those targets become illegal, the spell won’t resolve and you won’t get to draw a card.
- 22 January 2011You choose the order of the cards you put on top of your library.
- 25 February 2015You can cast Gravepurge with no targets. If you do, you’ll just draw a card. However, if you cast it with at least one target and all of those targets become illegal, the spell won’t resolve and you won’t draw a card.