> At this point the currency/speculative/prestige value is almost all of the value of gold
It isn't a currency, it has no obvious potential to be a currency and if you own it you are either a government or insulted. At best, only speculative value could be a factor of these 3, and I don't think the serious money that sets the price is speculating - and gold is a terrible market to speculate in, so they probably aren't setting the price as much as going broke.
The value of gold is set by how hard/easy it is to mine.