There are tens of thousands of different gold suppliers (biggest bunch are Chinese) and they all have different total cost levels across a very broad range. So much for supply; gold demand is mostly jewelry and fashions change so if it's no longer 'chic' and nobody wants to pay more than $100, there will still be sellers. OK, very few but some. Historically --over the past couple centuries-- gold's price in 2014$ has averaged about five or six hundred dollars.
It would make a great commodity short, wouldn’t it?