As long as Trinisphere 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.)
Near Mint - $27.400
Lightly Played - $21.900
Moderately Played - $19.200
Heavily Played - $16.400
Damaged - $13.700
Near Mint Spanish - $27.400
Lightly Played Spanish - $21.900
Moderately Played Spanish - $19.200
Heavily Played Spanish - $16.400
Damaged Spanish - $13.700