Can we put an upper limit on the value by saying that it can't be worth more than it costs to destroy trust in the block chain by inserting invalid transactions

Can we put an upper limit on the value by saying that it can't be worth more than it costs to destroy trust in the block chain by inserting invalid transactions? If that would only require 50% of the mining hardware and some 10s or 100s of transactions (e.g. an hour a day or even a week of power). I don't know what it would cost to do that, but if it was only recouping sunk costs, and future income for the miner then it should be relatively easy to calculate even if it changes all of the time. edit: I don't see how as a store of value it could be worth something that is effectively uncounterfitable and well established like gold ($7T), which would set a $350k maximum. As a transaction medium BTC wouldn't be a good choice anyway even as a first mover.