bitcoin is a currency and nothing else. and because this currency is new and is still growing and being adopted, its price rises which means it attracts speculators who invest in this currency. that doesn't change the nature of bitcoin though.
This cost represents the lowest price that bitcoin can functionally go.
and history has proven many times that price can and will fall below the creation cost (aka mining cost) of bitcoin as it has always fallen big time after its bubbles while the mining cost remains much higher.
in other words creation cost has nothing to do with how low price can go or how much it should be.
and it is a very common mistake among newcomers. the thing is you are looking at it upside down. price doesn't change based on cost, the cost changes based on price!
meaning if price is $10 then the cost will be a little less than $10
if price went up to $20 then the cost adjusts and will be a little less than $20
and if price fell down to $5 then the cost again readjusts and will be a little less than $5