Right now they're exploring and evaluating. It will take quite a number of more years until such things will become feasible economically.

On the other hand, people should read more about what the universe is made of and how it works. Then they'll understand that this kind of resources are generated in the universe as we speak, by the big stars exploding. So they're not limited at all to what we have on earth. The only problems would be the cost of bringing them onto earth vs the money they can get for them and maybe the (very-long term) impact of having different ratio of elements down here.