I hate to be the one to break the news to you fellas, but bitcoin @ $1 is just as useful as bitcoin @ $400.
There's truth to this. There's no "reason" bitcoin has to be valued high, it's just up to what folks are willing to pay for it. Folks are just gambling that the long term value is high.
so we agree that bitcoin have value. Good.
now 12.5 million coins (give or take a few) for 6/7 billion earthlings = scarcity
according to the of economics, this makes bitcoin rare and therefore valuable. How valuable will depend on its ubiquity.