Cheapest priced copy (Edge of Eternities): $0.35 at Card Kingdom, near mint, their price list as of .
Mental Modulation 
Instant · Common · Edge of Eternities · #67
This spell costs {1} less to cast during your turn.
Tap target artifact or creature.
Draw a card.
Legal inCommanderBrawlStandardPioneerModernLegacyVintagePauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Edge of Eternities | 67 | Common | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 25 July 2025If the target permanent is an illegal target as Mental Modulation tries to resolve, it won’t resolve and none of its effects will happen. You won’t draw a card.
- 25 July 2025To 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. The mana value of the spell remains unchanged, no matter what the total cost to cast it was.