Isn't what we are charged for our NBN an arbitary figure that in no way relates to the true costs for each customer?
How ever NBN Co and the ISP's and government choose to spin it the fixed cost of providing the NBN connection for each premise or business cannot be the same. It must vary between the easiest to reach customers in high density areas and those in the sprawling older suburbs of Melbourne and Sydney. Factors of ten or twenty times more costly!
You also need to add to this the cost of the backbone (back haul) connections and to the servers/data centres. Again depending on where the customer is the infrastructure costs to get the service from a data centre in Sydney to say Manly and Tony Abott's electoral office vs a farmer near Tamworth are also greatly different per customer.
None of these costs really relate to the actual volume or speed of data.
The speed and volumes of data that can move around the NBN is infinitely greater than what we can concurrently consume - since most of us sit at the end of a dodgy piece of copper wire. So the current tiered speed and data volume pricing is just an artificial construct. One that for many users per above delivers no economic gain if you don't need the extra speed! We are simply being asked to pay extra now with the new NBN services for the potential we might choose to use, as has been pointed out in other comments here.
The reality is that the NBN is not a true commercial enterprise whether you are A BIG "L" liberal or a small "l" liberal. If it was only the approx the 60% of Victorian and NSW customers who live in the big cities of Sydney and Melbourne and a few more in QLD etc would ever get the NBN.
The NBN is more a social experiment where the rest of Australia also gets the NBN - at a substantial subsidy due to the generosity of mainly Sydney and Melbourne and some in the other cities.
In my personal circumstances in a rural location it would have been better to bring the fibre into the local exchange. While Telstra and my ISP can't say it is a lack of exchange capacity that holds our community back. Unfortunately slow connection speeds and lack of capacity are not well understood by most voters. Any way now thanks to the generosity of Sydney and Melbourne the new fibre network passes 5km to the east of town to save their costs. All is not lost! Close upon the route will be a new tower to beam microwaves around a whole network of towers in the district to service not only all of us who live within a 2km radius of the old exchange but those further away!
I'll keep Choice up to date with the outcome of our giant wireless NBN and how it handles the many thousands of customers all on it at once!
And to be fair I understand just as the NBN is going to charge exactly the same for the service as though it were in central Sydney. Although why you should pay extra for a faster data rate on wireless when you actually use less connection time to consume the smae amount of data remains a mystery!