Until end of turn, your hero gains "Whenever you draw a card this action phase, deal 1 arcane damage to any target". (Brainstorm itself does not have an arcane damage effect. It is not modified by arcane damage modifiers.)
Near Mint - $1.00
Near Mint Spanish - $1.00
Lightly Played - $0.80
Lightly Played Spanish - $0.80
Moderately Played - $0.70
Moderately Played Spanish - $0.70
Heavily Played - $0.60
Heavily Played Spanish - $0.60
Damaged - $0.50
Damaged Spanish - $0.50