Meet the Makeblock mBot Ranger: a three-in-one STEM robot that can serve as a robot tank, 3-wheeled racing car, and self-balancing 2 wheeled vehicle. You can program the robot from your iPad or laptop. The tank can handle a wide variety of terrain while the racing car can run/spin fast.
The mBot Ranger Robot Kit comes with a visual programming interface. It is based on the Arduino Mega 2560. You get 5 onboard sensors and 10 extension ports. This robot ships in July for under $190.