Where does one get these circuit playground things ?
The company that makes and sells them is Adafruit. You can buy a classroom pack or they are sold individually. If you buy the classroom pack or purchase at least $250 worth of them, there is a bulk discount available as part of a partnership with code.org and Adafruit. You can find more information on that at the bottom of this page..
This discount has been around for a few years, but the last time I used it was last year at this time, so it should work, but I haven’t personally verified it in the last few months.
p.s. I should add that if you want to purchase one to try it out, you can usually find individual ones on Amazon that may ship a little quicker especially if you have Prime.