I buy used graphing calculators frequently. I lend the TI 83 calcs students; they hold on to them for several years to use in math and science classes. I keep a set of TI 84 calcs in class. Teens forget their devices. We use the TI 84 calc with EasyTemp sensors, as digital thermometers, too. I have had the best luck buying used graphing calcs from Good Will online. Really. I tried eBay and Amazon. Both times, the less expensive calcs had gritty keys. Boooo!
How much do new calcs cost?
Now, before I bid, I check to see the calc powers on and the cost of shipping. My target price for a TI 83 is $15 and $35 for a TI 84. I usually buy a lot of TI83 models to get an individual price of $15. I just bought TI 84s. The price is about the same as eBay; all the calculators power on and work.



















