Amazon offers the Hot Wheels Ai Intelligent Race System Arkham Asylum Chase Edition Starter Track Set for $100.42 $99.99 with free shipping. That's $50 off list and the lowest price we could find. It features two smart cars (the Batmobile and a Gotham City police car hijacked by the Joker), Batman- and Joker-themed controllers, authentic sounds, and 24 themed track pieces.

Update: The price has dropped to $59.07.