My school, for some reason, requires it's math students to own Graphing Calculators. I've been to an office supply store and most of them are at least $100 (Texas Intruments). Although I saw a Casio for just $50. I'm not sure why it's so much cheaper, but that's my main choice right now. This calculator is going to have to last me for years with frequent use. It has to be reliable (it can't die in a middle of an exam). I however, don't want to spend more than $100 (not including tax in US dollars). Since this is a science forum, I was wondering if you have any suggestions that would fit my needs? Any suggestions would help, thanks.