I still have and use my TI-84+ that I purchased when I started college. As a professional I use it here and there but rarely for anything that actually needs more than a basic scientific calculator. During college (civil engineering) I used many of the more powerful functions like matrix math stuff. In high school, I don't think I used a graphing calculator once. Just doesn't seem necessary to teach geometry and algebra 2 in my mind.
Yea, I loved by TI91 (I think that was it's designation); very durable, long battery life, a real work horse. I still have it. Don't remember how to to anything on it. The thing is, a full computer, python notebook, and keyboard are quite an advancement over that even. I get that $100 is high, but it's in the range of other BS like always-new textbooks. My only regret about these calculators is that they really are old tech now. In almost any industry or research we don't use calculators almost even, we always use full laptops. Kids should train on the best tech we use in the field, that's the laptop.
