It is indeed hard to please everyone.
We advertise all our prices as exclusive GST, GST and inclusive GST. Some customers tell me "what is all this crap, just tell me how much I have to pay". We have a private tax ruling (which by now is presumably public) that states; The integrated 150 hour CPL course is GST free. The 200 CPL incurs GST. The Grade 3 Instructor Rating is GST free. The G2 and G1 incur GST. And yes, the GST exclusive price is the same for everyone regardless of whether GST is added or not.