Cheapest priced copy (Mirrodin): $2.79 at Card Kingdom, near mint, their price list as of .
Gate to the Aether 
Artifact · Rare · Mirrodin · #174
At the beginning of each player's upkeep, that player reveals the top card of their library. If it's an artifact, creature, enchantment, or land card, the player may put it onto the battlefield.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
1 printing · $2.79 to $6.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Mirrodin | 174 | Rare | $2.79 | $6.99 |