Hurro, people.
Due to the Melb model, you have to complete the undergrad part (3 years) with an average of at least 65% (for example) to get into the master's program.
If you don't achieve this, does that mean you basically have a half-assed useless degree and you've wasted 3 years?
If you're going to university with the aims of getting a 65 average, it's three years wasted regardless. You're at Melbourne, man! Make something of it.
I'm not sure about eligibility criteria for Masters programs because I'm looking at an Honours year -> PhD at the moment. I know for Honours, to be competitive, you need to have around an 85% average with extra stuff to make your application look good, which is why I'm trying to get a volunteer internship for second year.
For your reference, an Honours year is the alternative to a Masters, and they'd both be rather competitive to get into.