Thought I'd share this experience, because I am sure others will benefit if they follow a similar path.
I am with Vodafone's "Smart $45" plan and I get the following;
Plus an extra 1GB of data for the first 6months, which finishes this month.
I was considering 2Degrees $39 pay monthly plan (with extra 1GB data and extra 100mins bonus);
..But was sad I would lose the Best Mate, network coverage (?), and paying for seconds rather than rounded-up-to nearest minute.
So called Voda and asked if they can match it. They did! They offered an extra 1GB and an extra 100mins calling on top of my Smart $45 for free for life.
They get the thumbs up from me.