Id be extremely surprised to see anything other than a MC on prices and incomes policy in an HSC exam.
Not only is it irrelevant to the modern policy framework, but it is an obscure thing that is in the syllabus, and doesn't quite belong.
Make sure you know what it is, and know about decentralisation etc, but dont spend hours studying it.
Nonetheless it is in the syllabus and you are expected to know it.
I will take a different line than the one used by without wings. I believe it is possible to predict what is in the HSC. Not necessarily what each question is, or necessarily what is going to be covered, but you can say what is more likely to be in it than what wont.
For example I would say that it is highly probable that there will be substantial questioning on labour market reform.
The only thing is that an estimation is just that. You cannot take it for granted, but you can use it as a guide for utilising your study time effectively.