The way I see it this may reach a fairly stable level but as Robert has pointed out the Earths population continues to grow and therefore demand is perpetuated. OEC equipped two strokes will not only save their health but make it more affordable. Vanadium power cells have a similar promise and appeal for third world countries and first world countries alike. As do fuel cells which when used in a automobile have shown to produce economy of about 100 miles per gallon with no pollution. Yes it generally and historically speaking is a cyclical market but in my experience each cyclical low is followed by a high but each high is getting higher and so are the lows.
Gold is the most manipulated resource on earth and seems genetically imbedded in the human psyche.
But take away that fascination and we are left with just another commodity. However you just can't build a computer or a car without platinum or tantalum. The wheels are made from magnesium alloy. Fibre optics relies on rare earths such as Cerbium. All I can say is go the tech stocks for they drive demand for most of this stuff.