Cheapest priced copy (Dominaria): $0.79 at Card Kingdom, near mint, their price list as of .
Thran Temporal Gateway 
Legendary Artifact · Rare · Dominaria · #233
{4}, {T}: You may put a historic permanent card from your hand onto the battlefield. (Artifacts, legendaries, and Sagas are historic.)
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
3 printings · $0.79 to $3.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Dominaria | 233 | Rare | $0.79 | $0.99 |
| Dominaria Promos | 233s | Rare | — | $3.99Out of stock |
| Secret Lair Drop (Doors of Indecision) | 2850 | Rare | — | — |
One ruling from Wizards of the Coast
- 27 April 2018A card, spell, or permanent is historic if it has the legendary supertype, the artifact card type, or the Saga subtype. Having two of those qualities doesn’t make an object more historic than another or provide an additional bonus—an object either is historic or it isn’t.