It IS undervalued, extremely undervalued, due to ego-fighting between weak effeminated freaks.
I don't think so It's more: The current use of Bitcoin does not even justify $1000, if you apply the Quantity Theory of Money, like this forum member did (his estimation for a fair price is about $200-250).
But I think all users that bought Bitcoins for more than - let's say - $500 are speculating that in the future there will be a much larger user base. But $100K would be already a order of magnitude where we would need a large portion of the world population using Bitcoin regularly. And I think it's not at all sure that that will occur.
We can do the math: If for the current user base (5-10 million) $250 is the "fair price" according to the QTM, then for a fair $2500 price we would need 50 to 100 million users (currently impossible without advanced scaling features or a massive block size increase to 10 MB or more), and for $100000, 2 to 4 billion.