I guess the WA Government was a bit naieve when it
maintained a royalty regime based on proce rather than
tonnage.
A $7/ton would make better sense than a 7% of price
on the assumption that the price would stay above $100/ton
despite potential over production.
But I suppose that is why BHP & RIO employ marketing
managers at a $mil/year while the WA Government pay
a lazy $150K a year for their Royalties' specialists.