Cheapest priced copy (Time Spiral Timeshifted): $0.35 at Card Kingdom, near mint, their price list as of .
Void 
Sorcery · Special · Time Spiral Timeshifted · #105
Choose a number. Destroy all artifacts and creatures with mana value equal to that number. Then target player reveals their hand and discards all nonland cards with mana value equal to the number.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
3 printings · $0.35 to $17.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Eternal Masters | 211 | Rare | $0.49 | $0.49 |
| Invasion | 287 | Rare | $0.69 | $17.99 |
| Time Spiral Timeshifted | 105 | Special | $0.35 | $3.49 |
2 rulings from Wizards of the Coast
- 8 June 2016The target player is chosen as you announce Void, but the number isn’t chosen until it’s resolving. No player may choose to take actions between you choosing a number and the rest of Void’s effects.
- 8 June 2016You can choose 0. Artifact lands and most tokens have mana values of 0, for example.