Best Buy has the K'nex Mario Cart Wii Yoshi vs Lava Plumes & Mario vs Piranha Plant Building Sets for $30 with free shipping. Includes both Yoshi vs Lava Plumes and Mario vs Piranha Plant. Includes Bullet Bill, a mushroom, an invincibility star, a green turtle shell and has 250 pieces. $37 and up everywhere else.
Walmart has K'nex Super Mario Ghost House Building Set for $40 w/ pickup