While I think it's true that BTC won't fall below the cost of mining 1 BTC, that's not really saying anything. If BTC falls below the cost of mining people wil

While I think it's true that BTC won't fall below the cost of mining 1 BTC, that's not really saying anything. If BTC falls below the cost of mining people will stop mining and the network will adjust to the reduced difficulty, making the cost of mining drop. A problem is that if too few people mine, the network becomes easy to compromise. That's a problem that bitcoin has, and other currencies (and things like gold and silver) do not.