How would you suggest Scribophile allow their prices to fluctuate with a bitcoin's value? How should they measure the value of a bitcoin? Setting a target pric

How would you suggest Scribophile allow their prices to fluctuate with a bitcoin's value? How should they measure the value of a bitcoin? Setting a target price in USD is the obvious answer, but then bitcoin becomes merely a way of exchanging dollars, not a currency in its own right.