How much lower would the price have fallen in the absence of Rockefeller's monopoly pricing?
Standard Oil - Wikipedia
"In 1904, Standard controlled 91 percent of production and 85 percent of final sales.
"Most of its output was
kerosene, of which 55 percent was exported around the world.
"After 1900 it did not try to force competitors out of business by underpricing them.
[39]
"The federal Commissioner of Corporations studied Standard's operations from the period of 1904 to 1906
[40] and concluded that 'beyond question ... the dominant position of the Standard Oil Co. in the refining industry was due to unfair practices—
to abuse of the control of pipe-lines, to railroad discriminations, and to unfair methods of competition in the sale of the refined petroleum product.'"