>>lewisf+(OP)
Standardization is inevitable. Teachers cannot and will not use calculators unless the module they are using (in the textbook or purchased separately) contains button by button instructions that work on the exact model of calculator used in their classroom. Something needs to be done to break the TI monopoly, though. There's no reason to pay that much for such primitive functionality, and the need for dedicated devices that can't be used to cheat won't go away.