> Show me a highschool math problem you can't do on a $12 Casio scientific like the classic FX-300MS

There isn't one.

The TI-83 is just a $160 tax on every high school student. There is precisely zero use in a graphing calculator before university.

If you ever need a plot of literally any function you'd be plotting in high school, you should be able to do a very quick, very rough approximation by hand. If you can't, you haven't learned the material.