I will add to this list and links as ideas come in. We may be the lucky country but surely stupidity will extract a price one day. All these issues would make articles in their own right.
 AUSSAT $700mill losses & debts rolled over into Pay TV 1990’s,
 $6Bn Collins Class Submarines 1990’s – duds we are still stuck with,
 Electricity privatisations started in 1990’s – looking at our ballooning power prices would we have been better off keeping the old State Electricity Commissions? Despite the feather-bedded unions.
 MRET scheme making 3 worse and harming our electricity grid into the bargain – ongoing multi $Bn’s as taxpayers fund wind & solar that can never power our 24/7 grid,
 Defence purchases eg MRH-90 helicopters $4.2Bn,
 Frequently delayed and poorly performing F-35 fighters $24Bn alone,
 Eastern States Desalination plants ~$20Bn,
 Rudd Labor watering down border laws $11.6 billion over five years,
 Decades of anti-damism – after not building the Franklin Dam in the 80’s,
 Antifracking hysteria affecting gas exploration policy in face of rising prices,
 Building the Education Revolution $16.2Bn – More money for Education = worse results,
 Adelaide Hospital third most expensive building in the world $2.1Bn,
 Inability to control rogue unions like CFMEU which affects 12 and all other construction est +$10Bn,
 NBN a future $100Bn mediocre performer?
 Buying 12 French submarines before even a prototype is built future $50Bn,
 The GST carve up which rewards the basket case States SA & Tas.
 Various States and GreenLabor anti-nuclear policies.
 Climate change policies – have a effect in 4, 7, 10, multi-$Bn’s.
 Just been told about this from Toytown 17 Jan 2017. Amazing construction stuffup with Sydney Metro NorthWest rail bridge.
“Investigation reveals ‘disappointing’ failures in Skytrain construction”
Please send in useful links and analysis. I must have been half asleep to leave the Rudd MkI Pink Batts and School Halls stimulus projects off the list. Also forgot to add GreenLabor’s Murray Darling Basin Plan to waste more dam water to the ocean.