I think that the most common way to value Bitcoin is like valuing other currency by another currency.
Seeing to it that we all know all the factors that causes or affects supply and demand equilibrium.
Also the time we hold bitcoins. Time is very important factor.
We have to be honest here. Everyone wants money. But there is small number of ways to make your money doubled. So one of the way is having concurrency. But there is another advantage in having bitcoin in a starting of a new circle. that will 4x your money.