OK.

lots of people confuse a $75-$120 / kWh cell price for grid scale battery installed price, which these days is about $300 / kWh.

1 gigawatt hour of installed BESS therefore at current prices is roughly $300 million.

Snowy 2 is 350 gigawatt hours, which would cost $105 billion in equivalent batteries which is about $150 billion in Australian dollars, or ~7x cheaper per gwh.