Sphinx's Tutelage 76/272 (Magic Origins)

Whenever you draw a card, target opponent mills two cards. If two nonland cards that share a color were milled this way, repeat this process. {5}{U}: Draw a card, then discard a card.

NM - $1.40
LP - $1.10
MP - $0.90
HP - $0.70
DMG - $0.70