ecstasy, noun: an emotional or religious frenzy or trance-like state.
Once upon a time, I held an ounce of gold in my hand and reflected on it for a couple of minutes, and I heard its song. This post was prompted by hearing that song again recently (well, that and worrying about inflation).
I think there's more to the valuation of gold than the economists think. I think it speaks to people on a primeval level, once you've tasted it.
It is one thing to have been told that gold is dense, and to know it numerically. It is another to feel its weight in your hand. Physics gives an inherent gravitas to it, a seriousness. It isn't easy-come-easy-go; the effort of picking it up forbids it. You can't light cigars with it or "make it rain" at the club. In your hand it has the feeling of a solidly-made tool, of a good hammer or your grandfather's fixed-blade hunting-knife. It feels durable, permanent, faith-worthy. But it is a faith which demands works, the bearing of burdens. It is a faith that demands care, that your purse is kept well-mended and free of holes. An old-style faith, of the keeping of covenants.
The color is that of warm sunshine; neither the pale cold sun of winter nor the killing white sun of the desert. It is a life-giving color, the color of grain ready for harvest, of baked bread, of beer, of calories against the cold, of abundance, and of the weather under which crops are abundant and one relaxes in simple contentment. To laze in the sun is not an instinct exclusive to man, but shared with the animals (particularly cats, among man's companions). Gold calls to mind this universal experience. Gold-worship is sun-worship writ small.
Can you impart these feelings to your players, through verbal description? I dunno. Maybe. Seems worth trying. It certainly makes a lot of sense of the willingness to go into dark holes in the ground and fight terrible things to get it. I do think maybe D&D cheapens the value of gold by making it the standard currency, and one could make silver the standard and have gold replace platinum to boost its impact.
I could also see a fantasy coinage scheme where you name your coin-types celestially; gold suns, silver moons, copper planets, iron stars. If you wanted a more supernatural take on it, you could make gold literal fragments of the sun god, which would explain why magic research consumes it in great quantities. This could also be spun to provide in-world justification for "1 XP per GP".