global mine production is 10t per day. 120t/day from single 1gw e plant does sink value substantially, but is a drop in the bucket compared to 80k tons of copper/day. Gold is a better copper I think, so maybe a floor value of $20/kg. But to subsidize fusion energy by 20c/kwh, it needs to stay above $11/oz . Gold is also a better silver, but silver production is 80t/day, and so gold is unlikely to hold that threshhold value.

A bigger deal is that we are collectively too politically stupid to have "golden goose fusion". Our blessed oligarchs deserve better than their heathen oligarchs, and it is perfectly normal to diminish and warcruise them. Nuclear power already isn't war resilient, and destroying one is something Ukraine has seen propaganda value in doing due to media control that would blame Russia for it. So, our collective stupidity is already at extreme levels. But the play in golden goose fusion is buy all the ultra cheap gold after mine closures, and then destroy all the golden geese. Destroy all attempts to build new ones.