There are not many arduino robot kits available. Especially ones that can roll around and easily be reprogrammed. But here are a few kits that are easy and fun to build and can take a student from novice all the way to expert.
The Mbot STEM Robot Kit is a simple programming robotics toy. The kit can be assembled in about an hour and then programmed with the mBot graphical coding tools. The Mbot is also expandable using new sensors. But the kit is a bit difficult to change physically. Mounting new components can be difficult with the steel frame.
mBot costs 39-95 dollars.
The LittleBot Budget is a simple Arduino programming robot kit. It can be 3D printed from scratch or built from a kit. Once it is assembled the kit can be programmed with Arduino or Scratch Tools.
As the students' skills grow the LittleBot Budget can have accessories added that can add new skills and programming challenges for kids to try. The arduino kit is also supported with a number of tutorials for assembly as well as the various expansions for the kit.
The LittleBot Budget costs 35-79 dollars
The Zumo 32U4 Robot Kit is a highly integrated, user-programmable and customizable tracked robot. It is a metal framed robot and can be programmed with the Arduino Environment with little difficulty.
The robot is small and packed with power. Designed to be used in robot sumo competitions this little arduino robot can pack a punch.
The Cost of the Zumoe is $140