Would it be possible to set a fee based on the market $ price of DASH.
I understand the impulse, but I think it is unwise for any crypto to price its features in fiat units. The point is to replace fiat world-wide imho, not to tether (ahem) crypto to one country's centralized fiat price fluctuations.
Most people alive today (outside Zimbabwe or Venezuela) have yet to notice that fiat is not a store of value. Crypto
is money and fiat
is not, but we are all bound by old habits.