Cheapest priced copy (Secret Lair Drop): $44.99 at Card Kingdom, foil, near mint, their price list as of .
I've Brought You a Gift 
Trinisphere
Artifact · Rare · Secret Lair Drop · #2838
As long as this artifact is untapped, each spell that would cost less than three mana to cast costs three mana to cast. (Additional mana in the cost may be paid with any color of mana or colorless mana. For example, a spell that would cost {1}{B} to cast costs {2}{B} to cast instead.)
Legal inCommanderModernLegacy
Restricted inVintage
Not legal inBrawlStandardPioneerPauper
8 printings · $44.99 to $299.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Double Masters | 303 | Mythic | $49.99 | $69.99Out of stock |
| Darksteel | 154 | Rare | $59.99 | $109.99 |
| Kaladesh Inventions | 52 | Special | — | $299.99Out of stock |
| Eternal Weekend | 2025b | Mythic | — | — |
| Secret Lair Drop | 1485 | Mythic | $49.99 | — |
| Secret Lair Drop | 1485★ | Mythic | — | $44.99 |
| Secret Lair Drop (I've Brought You a Gift) | 2838 | Rare | — | — |
| From the Vault: Exiled | 15 | Mythic | — | $47.99Out of stock |
2 rulings from Wizards of the Coast
- 7 August 2020To determine the total cost of a spell, start with the mana cost or alternative cost you're paying, add any cost increases, then apply any cost reductions. Finally, apply Trinisphere's effect if the mana component of the spell's cost is less than three mana. The mana value of the spell remains unchanged, no matter what the total cost to cast it was.
- 7 August 2020If Trinisphere leaves the battlefield or becomes tapped or untapped as a cost to cast a spell, this cost is paid after you've locked in the total cost.