I think it's very simple.The answer to this question is rather simple and it lies in basic economics: scarcity, utility, supply and demand.
By definition, if something is both rare (scarce) and useful (utility) it must have value and demand a specific price, with all other things being equal.
Take gold, for example. Why does gold cost as much as it does? Put simply, it is relatively expensive because it is rare, hard to find and limited in supply (scarcity). Gold also has some uses to which consumers derive satisfaction from (utility).
The combination of these two elements creates value by which price is determined based on the market’s supply and demand.