This is a hideous way of describing the value of Bitcoin.

The cost of mining rises and falls because of the change in Bitcoin's value, not the other way around.  The fact that electricity was used in order to create Bitcoin has no effect on Bitcoin's value, apart from the sunk cost fallacy that may be exerted by miners (as well as speculators).

Also, the block reward is not a permanent feature.  In about 123 years, it will no longer exist.