[jerf]

Common myth, but it's false. Paper currency's true value is that the issuer is obligated to do something in return for it. Since that's usually governments, paper currency's true value is that you can use it to pay debts to that government. Everybody in the world can stop using US Dollars for anything else, but they'll still be useful for that, because that is basically the definition of a US Dollar. Says so right on the bill.

You can set your philosophical bar of "real value" higher than that, but there's not much light of day between that and a standard so high that it's not even theoretically reachable, at which point I stop caring about your definition of "real value" since when nothing can meet the bar, it's not a useful concept anymore. (But I do mean "not much", not "zero".) In the end, all value stores are transient on a century timescale, and I don't see that changing. Even gold hasn't had anything like a constant value. But for a putative currency, BitCoin is distinctive in its total disconnection from a concrete value.

[caf]

Governments are typically not bound to continue accepting payment in today's currency tomorrow. There have been many cases of government arbitrarily redenominating their currencies and/or their debts.

[URSpider94]

I don't think we're really arguing here. My comment was meant to be somewhat tongue-in-cheek, but nonetheless most currencies share the property that their value in trade is decoupled from their inherent value. Back to the OP's question, there is no such thing as a real value of a BitCoin, it comes down to how much someone else is willing to exchange (in barter, currency, gold, whatever) at any particular moment.