The problem with your example is that there is no demand, so there's no reason for anyone to buy any bitcoin at any price and so no expectation that you could sell your 400 bitcoin for $160,000. The driver of speculative value for bitcoin is future demand, i.e. what the demand is expected to be down the line. This is partly driven by speculation/greater fools right now. But its also partly the potential of Bitcoin to be a global currency.