I think there are better ways of getting people to do maths/sci than reduced HECS
Definitely. Lets not forget our fees are already subsidised by the government. We might pay 8k for our course as a result of this but it still costs international students something like 20k, the government is still paying for a fair portion of it. We went into this in depth in the previous thread about this.

Most people put their fees on HECS-HELP and forget about it. It's not like anyone who was a citizen/PR was choosing their course based on the cost (rightly so).
However, my problem is that science is now in
band 2. Band 2 along with things like Engineering and IT. As far as i know, the bands are based on skill shortage and the salary people with that degree make on average. Obviously, science wont be generally pulling law or medicine money. I'd argue its more in shortage and has a lower monetary pay off than Engineering(iffy) or IT though. I think it should be in band 1 personally.
~$8 000/
$30 000 = ~25% . So, we're still only paying a quarter. I really wouldn't want to see that move post 33% or 40% for any course except the ones that'll pull you megabucks like the ones in band 3.
Even if it was taught "competently" though, i dont know how big of an increase we'll get. We already have a lot of people who do very well in math going over to commerce or other fields that aren't science. Theres only so much you can do to force demand to increase when you have plenty of other people aiming for the more prestigious or better paying careers (which is a whole other problem now entirely).