Readers of this thread may be interested in lower cost options. I built a middle school robotics curriculum around Dexter GoPiGo robots: https://www.dexterindustries.com/gopigo3/

While you can do visual/block based coding on these, it also has built in Python support and the whole curriculum I ran was Python based.

My criteria for selection of this platform included: - support for Grove sensors - flexibility in machining own parts if desired - Python support - rPi based

(no affiliation with this company, just a positive real world end-user/educator experience)