I like Edison, for $50 or less in bulk. It has 2 motors, sensors, some LED's and you can build upon it with Lego's to make different objects (ice cream truck, merry go round, ferris wheel). You could even hook one up to another. It has a unique feature in that it downloads the program via sound (audio cable). You can program it at 3 different levels : a basic block form, a scratch style, and their version of Python. It is browser based soYou can use a computer, chromebook, or a tablet. They have some good education support and some lessons to get you going. It fits in the palm of an adult hand.