Cheapest priced copy (Commander Legends: Battle for Baldur's Gate): $0.69 at Card Kingdom, near mint, their price list as of .
Midnight Clock 
Artifact · Rare · Throne of Eldraine · #54
{T}: Add {U}.
{2}{U}: Put an hour counter on this artifact.
At the beginning of each upkeep, put an hour counter on this artifact.
When the twelfth hour counter is put on this artifact, shuffle your hand and graveyard into your library, then draw seven cards. Exile this artifact.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
13 printings · $0.69 to $10.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander Legends: Battle for Baldur's Gate | 727 | Rare | $0.69 | — |
| Aetherdrift Commander | 79 | Rare | $0.79 | — |
| Throne of Eldraine | 54 | Rare | $0.79 | $1.99 |
| Throne of Eldraine | 346 | Rare | $4.49 | $10.99 |
| Modern Horizons 3 Commander | 189 | Rare | $0.69 | $1.49 |
| New Capenna Commander | 226 | Rare | $0.69 | — |
| Outlaws of Thunder Junction Commander | 100 | Rare | $0.79 | — |
| Throne of Eldraine Promos | 54p | Rare | $3.49 | $4.99 |
| Throne of Eldraine Promos | 54s | Rare | — | $3.49 |
| The List | ELD-54 | Rare | $0.99 | — |
| Secret Lair Drop (Kings Bay Clock Tower) | 2217 | Rare | $2.29 | $4.49 |
| Crimson Vow Commander | 108 | Rare | $0.79 | — |
| Wilds of Eldraine Commander | 99 | Rare | $0.79 | — |
4 rulings from Wizards of the Coast
- 4 October 2019Midnight Clock's first triggered ability triggers at the beginning of each upkeep, not just your upkeep. In a Two-Headed Giant game, an ability that triggers at the beginning of each upkeep rather than each player's upkeep triggers only once during each team's upkeep.
- 4 October 2019You can activate Midnight Clock's mana ability to pay the cost of its second ability.
- 4 October 2019Midnight Clock's last ability triggers after one or more counters are put onto it if it had fewer than twelve counters on it before those counters were put on it and it has twelve or more counters on it after.
- 4 October 2019If Midnight Clock leaves the battlefield while its last ability is on the stack, it won't be exiled.