Cast a random Lesson spell without paying its mana color. If that spell has X in its mana cost, X is 3. (As of today, there are 20 lessons. Perhaps look up a list and roll a d20?)
Near Mint - $9.900
Lightly Played - $8.000
Moderately Played - $7.000
Heavily Played - $6.000
Damaged - $5.000
Near Mint Spanish - $9.900
Lightly Played Spanish - $8.000
Moderately Played Spanish - $7.000
Heavily Played Spanish - $6.000
Damaged Spanish - $5.000