For Sale: Lego Mindstorms EV3 Robot, $300
Very fun Lego Robot that kids can build and program
Kids can learn early computer science concepts and robotics in a very fun and engaging way
Includes various sensors for color, touch, and infrared
Can be controlled from an iPad or kids can program it from a computer using the free EV3 software
I used the robots for a robotics program I did with my 5th grade Girl Scout troop, and they had a blast. The robot is used, but works perfectly and I've confirmed that every piece is included.

Sells for $350 on Amazon:
http://www.amazon.com/LEGO-6029291-Mindstorms-EV3-31313/dp/B00CWER3XY/ref=sr_1_1?ie=UTF8&qid=1400626081&sr=8-1&keywords=lego+mindstorms+ev3

You can download the accompanying software for free from this link:
http://www.lego.com/en-us/mindstorms/downloads/software/ddsoftwaredownload/