The Lego Mindstorms EV3 kit, coming in September, costs $349 and comes with more than 500 pieces. It has motors, light, color, and touch sensors, and a remote control. It can be programmed via Mac or Windows PC, and has iOS and Android support. Oh, and it's meant for older kids. How easy would it be for me to set up?
Taking the Mindstorms Brick out of its box: this central computer has an ARM9 processor, black-and-white LCD screen and speaker, USB, SD card slot, multiple inputs and outputs to motors and accessories, and uses six AA batteries.
Running Mindstorms software allows you to upgrade firmware on the Brick, see instructions for making other robots, and most importantly, program whole new routines for your robot, which can be downloaded to the Brick via USB cable.