How many electric vehicles can our current supply of lithium power?
You assume there is X lithium and all of it cost Y. And then there would be no lithium to mine. Thats not quite right. As you are ready to pay more, harder to get sources become profitable and become part of available reserves. Sea has almost unlimited amount of lithium, but it is about x5 as expensive to mine.
The total lithium content of seawater is very large and is estimated as 230 billion tonnes
(wiki)