It depends.
I’ll use some abstracted and simplified version to explain my point of view.
If Wakanda and Middle Earth mine Vibranium (which is Mithril btw), and both sell internationally for 100USD/kg+shipping, both get similar market share, depending on details like proximity to the customer, different grades, personal preferences etc.
Wakanda now invents a new mining laser, which reduces their cost/kg to 85USD/kg.
Middle Earth doesn’t want to lose the entire market and risk an uprising of the dwarves, as they just lost their entire industry. Middle Earth decides to pay the drwarves 20USD/kg of exported Mithril, so that they can try and improve their efficiency, and still keep their families fed.
Now Wakanda is undercut, and losing massive amounts of sales, Companies start layoffs, and Wakanda injects 20 Million USD in new refineries, increasing their output.
People not just internstionally but even in Middle Earth start buying Wakandan Vibranium. Instead of constantly increasing support, Middle earth decides to put Tariffs on Wakandan Vibranium, to protect at least the national market from Wakandan influence.
Well seems like all car companies are somewhat subsidized/supported. I don’t know how difficult to detangle the presumably many different levels of that are, especially internationally.
But if the EU were to subsidize “just” 500$ per car sold, and China 50.000$ per car, it would be impossible for european car makers to compete on an otherwise equal field.
Now I have no Idea how supported which markets are, and I’d presume I grossly exaggerated the difference, and it may well be the other way around. I have not found detailed analysis of this though.