Where do you take the number $500k from? Just imaginination, some sort of calculation?

I mean if bitcoin should be implemented into the financial service chain in terms of online transactions from e- commerce or as a "behind the scenes financial vehicle" in services like Western Union then the amount of money transfered by them has to fit into the existing 21m coins. So for that to be possible the price would have to rise. But to $500k?

Aside from that people are just way too risk averse and think that only the fiat in their bank account is real money instead of seeing it a another trading position. (Which it is, its a bet that fiat currency will rise in value- a very stupid one considering the amount will never shrink.)