My expenditure on burgers in the last 10 years is less than $12, it's $0.

That article's a little misleading. The burger cost they quote is based on a curent estimate of production being possible at $80 per kg - no one's currently producing it at that price, The article starts by saying "And now it's cheap, too.", but then backtracks dramatically. $11-12 per burger is hardly cheap, and as they later admit, it's not commercially viable.

No doubt prices wil come down much further, but it could take decades.

Here's the original article:

http://www.abc.net.au/am/content/2015/s4205857.htm

I've nothing intelligent to contribute to this discussion  Except I feel quite hungry now...

,As Renton would say ....I hope that helps  

 Yes! forgot that bit 

When Iceland are doing 8 for £1, let me know.