When I was in school, many classes were standardized on particular models such as the TI-83 and TI-85. On the first day of class, my teachers would always say "I teach using this model and if you don't have it, you are on your own". I didn't want to be on my own so I bought the recommended model.

In business, you can price based on "cost plus a markup" or you can price based on what the market will bear. In the case of TI, they price based on what the market will bear.