"Nothing is determined" yes it is, by supply and demand. if nobody wants to buy your turd the price is zero, as determined by the lack of demand.
Yeah sure, but what makes you so sure that a Bitcoin is more worth than my turd? Because currently everybody wants some?
Do you have reason to
know that it is not a ponzi scheme?
And if you want to know how an economy without inflationary currency works, then study the Austrian school of economics, again, it's obvious that you know very little to nothing about economics.
Economic theories are not proofable and many people with nobel prizes in economy failed while trading stocks or do you think Markowitz Portfolio Theory captures reality?

So you believe in Bitcoin backed up by theories about economy. And I believe in my (economic) theories. Nothing to battle about.
Well, people are buying bitcoin, but not your turd, that proves that it is worth more than your turd. Basic economics.
It's not a Ponzi scheme because there is no Ponzi. From wikipedia " Operators of Ponzi schemes can be either individuals or corporations", bitcoin is neither.