Bob
The Academic price is higher than the update price to discourage students and teachers from continually buying Academic, or for regular users, who might quality, from trying to save a few bucks by getting the Academic version.
Once a student or teacher has bought the Academic version they just update it the same way the rest of the world. The Academic pricing simply helps students and teachers to save a few bucks while jumping onto the "Adobe 18-month-update-cycle" income train.
The Academic price is higher than the update price
not in the US