The $400 figure was the last time I checked--it's a very illiquid market and I remember publicly accessible prices being delayed by months. But rhenium is extracted as a molybdenum impurity, itself an impurity in copper. Most (90%) of it comes from Chile, and the price reflects supply and demand, really. I don't know what the supply elasticity is like, but I suppose suppliers could buy back old copper or molybdenum to purify it if the price warranted it. And because it's an exotic metal, none of the production is artisanal. Gold, on the other hand, has about 25% artisanal production, because mankind has been mining it for thousands of years and the extraction process is simple and well known.