Just before the days where every high school student had a cell phone, everyone in class had a TI graphing calculator ... This is a great project to make the math workhorse of the classroom ...

For the lowest level courses, get the model you will eventually need in a later course (e.g., a student in MATH 1100 who will eventually take MATH 1160 should get a TI-83/84, but a student in MATH ...