I agree that using such a pigment for a small number of art objects would certainly be justified, like also the use of gold in art objects or jewelry, instead of its more valuable technical uses, for which there are no alternatives, e.g. in protecting electrical contacts from corrosion or in semiconductor metallization.

However, if instead of using this pigment in a few valuable paintings, it would be used in a high number of ephemeral sketches done for practice, that would be a waste.

Nevertheless, the high price at which the pigment has been launched is good, because it will probably deter casual use.