Kentaro, the Smiling Cat 13 (Betrayers of Kamigawa)

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.) You may pay {X} rather than pay the mana cost for Samurai spells you cast, where X is that spell's mana value.

NM - $4.20
LP - $3.30
MP - $2.50
HP - $1.70
DMG - $1.50