You take a gold coin down to the corner shop and they give whatever the price is now, $314, I guess. I don't know, I'm not interested in the daily fluctuations. Gold may be the only form of money left standing in a disaster and that's why everyone should have some. If you don't want any, fine, you can work for me when your fiat money hyperinflates. Go out there and cut firewood, tend the garden, I'll find something for you to do. :^)
I'm sure there are commodity traders who wheel and deal in these metals, but I don't think they feel any obligation to abide by any per/ounce bid containing a 3, a 1 or a 4 in it.
We live in a market economy. The market determines the price, from Mike Piazza's salary to an ounce of gold.
Gold's too esoteric for me. Chick Pea futures ... I'm there dude!
Good luck.
As an experiment, try making your purchases with gold for a week.