IB Corrupt?

Is it just a coincidence that the required calculator – TI 85 – for the IB is much more complicated to use and expensive than any calculator recommended for A level or equivalent?
Has someone at TI slipped someone at the IB a crafty backhander so that their very expensive calculator is the required one, and with a lot of questions based on the use of this specific calculator, you really cannot pass the IB without it.
The TI 85 costs £85, compared to £20 for I reckon is an adequate calculator for A Level.