VEX Robotics
I do like VEX Robotics. I just can't afford them. I last used them a couple of years ago when I started an Engineering Design class at a middle school. They are like the Erector sets of old, metal pieces of all shapes and sizes you put together with tiny nuts & bolts. But these now have motors, wheels, sensors and a microcontroller that you program. You have to download software to a Mac or Windows computer. There are 4 modes in programming : blocks, text ,VEX C++, C++ Pro. They have a lot of support and documentation for educators. Kits start at $600 (their newest version V5 is on backorder) or $500 for Legacy (older version and in stock). Some of their kits they say are good for 4 students, but I wouldn't put 4 students on one robot. There is not enough to do or things to work with. Look at how many controllers (brains) ; that is how many devices they can build and I would put at most 2 per device.