In a steady-state system, the price of a monetary asset is given by the "quantity theory of money", which states that:
P x Q = M x V, where
P is the price of the goods, Q is the amount of goods bought by the monetary asset, M is the amount of monetary asset in circulation, and V is the average velocity (the number of times per year that a given bitcoin is used to buy something).
Dump the velocity. and you are good to go. It has to be liquid, the owner needs to know that he can easily get rid of the bitcoins, actual trades are not needed.
You cannot ignore the velocity. If everybody would pay their bills the same day they get the money, instead of waiting to the end of the month, the same amount of trading would require 1/30 as much currency in circulation. If the currency it bitcoin, the smaller demand would imply a lower value per BTC.