>we can be pretty confident the S&P wont be at 50% of what it is today.
except that time the S&P dropped 57% (2007 to 2009 from 1,565.15 to 676.53)
>But is there any coherent explanation for why bitcoin should be priced at 2500 dollars rather than 2.5 dollars? or 2.5 cents?
Are you similarly skeptical about the price of gold? There is a universal need for a store of value which is not only insulated from global financial markets, but also a hedge against them. Due to mathematically certain scarcity and decentralized resistance to manipulation, crypto fulfils that need better than gold. Assuming that gold is priced primarily to fulfill this same market need, and that no gold is ever mined again, a bitcoin should be valued at $377,000.