Amazon has the Hot Wheels Mario Kart Piranha Plant Slide Track Set for $20 - $5 off coupon (check "Apply coupon" box) = $15 with free shipping on $25+ or with Prime. Target has it for the same price (Click "Save offer" on page; Exp 11/12, one-time use). Comes with a Luigi die-cast kart.

• Hot Wheels Dragon Drive Firefight Track Set for $13 after coupon (also Target)
• Hot Wheels City Wreck & Ride Gorilla Attack Playset for $11 (no coupon needed)
• Hot Wheels City Super Twist Tire Shop Playset for $13 after coupon
• 5-Pack Hot Wheels Disney Princess Character Cars for $15 after coupon (also Target)