These calculators (including the TI-89) are not worth the price. They just don't have any important features, unless you are doing statistics. And ALL of the features are better implemented in any of dozens of calculator apps for smartphones. That being said, these are durable and do what they are designed for, albeit for an outrageous price tag.More importantly though, why does TI think that this is a reasonable price for the same product that has been out for 15 years? It was great when it came out, but for almost $100 TI really needs to improve their product.