Australia isn't really a First World Country in the way Europeans (and I'm lumping you Poms in with them) or even 'Mericans think of it. We are more like Spain or Canada - a lot of space with relatively few people lounging around the edges and a lot of space in between. Good weather (Canadian winters aside), good food and some decent surfing if you know where to look. But nobody really understands how it works and very few really give a fuck.
Costs for just about everything are high here for reasons far to complicated to go into. In the case of telecommunications, a major factor is that its a bloody long way between Australians and what connects us* is pretty much all owned by one company who have systematically failed to keep the string both dry and taut.
What they have done is build out a lot of expensive wireless infrastructure in the hope we'd pay through our collective proverbial to make video calls to one another from taxis in downtown Sydney. The other infrastructure builders have pretty much followed this model.
On the plus side, I can cross three time zones without roaming charges or wondering whether I'll even be able to make a call because the local carrier doesn't talk to mine.
Swing, meet roundabout.
Last time I looked, mining employs under 8% of working Aussies, a lot less now, which is less than manufacturing and even I'm hard pressed to think of something actually made here. The majority of those work in the back office rather than at the coalface, so to speak, so your mates who work "on the mines" are a very small sample set. The immediate limit on the resource sector is not availability of raw materials, its demand and a failure of management to understand how their customers run their economies. Don't worry about us running out of stuff to dig up, that's the least of problems right now.
* For the benefit of non-Aussies that's a joke on the tag line of a Telstra ad campaign