No specific numbers, but I have friend who uses thick impasto style with oil paints. At one point he was trying out cheap and expensive oils and had a studio visit with the owner of a major gallery.
The first thing the gallerist did was point out every painting that used the cheap oil paint. Now he exclusively uses Old Holland brand oils. some of which list for 300-500 USD for 225ml.
MKL this is something as an artist or a platform I would make much clearer. You're right that if you look at materials alone its more than folks are willing to pay. Then there is artists time. You could show like based on materials plus time this artist would be getting paid $10/hr. this may help people to justify costs. However its not necessarily the best measurement (some artists are faster, more experienced are faster)
The first thing the gallerist did was point out every painting that used the cheap oil paint. Now he exclusively uses Old Holland brand oils. some of which list for 300-500 USD for 225ml.