I knew that!
What's funny is I use TPG and new all about the cost of my "unlimited" plan being $59.99 a month. Doesn't take much to know this as their advertising has the standard asterix and if you read the fine print associated with the ad, you'll see it's not $29.99 a month.
TPG also has the cheapest unlimited plan in Oz, cheapest mobile phones, and cheapest home telephone. I've been using them for almost 5 years now and couldn't be happier.