VivaLasVegas - Google is your friend. Go to the Neco site for more info on Bluegen... http://www.neco.com.au/index.php/fuel-cell/bluegenfaqs
Since it typically only uses about 20%-30% of the gas that a gas hot water system uses, it's hard to see there being a gas price increase so extreme as to render it uneconomical.
It's not the cheap price of gas that makes this a winner - it's how little gas it uses!