The cost to make something does not give it value.
I haven't read all the stuff here, but just about that: I would argue, that in the case of gold, bitcoin & co, it boils down to reduction of entropy. for gold, you have to find and combine all the tiny bits (atoms) to bigger chunks. That reduces the scattering, i.e. entropy. this needs energy! bitcoin: the low hash value is one of the purest forms of entropy reduction you can get. also needs energy.
so, only the cost of making something doesn't count, but it counts if its goal is to make something "special" or "unique".
Actually this is a really good point. Gold that is still in the ground isn't worth anything. It's only when it's dug up that it gets it's value because now someone put effort into transforming that lump of rock into something more pure and more beautifully shaped that the person who dug it up and other people now value. And this is as true today as it was back when the only use gold saw was as jewellery (imagine some guy finding a pretty rock and coming home and giving as a present to his wife saying "look what I found, isn't it pretty..).
The same could be argued about the calculated hashes.. By themselves they are meaningless and worthless but it's because someone did the calculations and found those numbers and gathered them into a blockchain that they were valuable to them and then to others.