I am not completely sure that Metcalfes law can used to price an asset class.

However, the stunning results posted by gbianchi and Peter R are sufficiently convincing, e.g. the close alignment of the data series in Peter R's graph, make me very interested to see just how the law can indeed apply. Especially considering much headroom the Bitcoin economy has with regard to transaction quantity growth over the next seven years.

You might get a stronger explanation by posting your issue in gbianchi's thread linked earlier.