Late last year NBN announced an immediate halt to any new Hybrid Fibre-Coaxial connections while it worked on "improving the service for existing customers", a move which was tipped to cost taxpayers between $420 to $790 million, according to NBN's own figures.

Today, NBN's half yearly result showed an increase of $450 million in costs to the HFC network - an increase that Shadow Communications Minister Michelle Rowland says isn't even including the costs of the "halt".