For the purpose of § 3430.1-1 of this title, commercial quantities is defined as follows:

(a) The coal deposit discovered under the prospecting permit shall be of such character and quantity that a prudent person would be justified in further expenditure of his labor and means with a reasonable prospect of success in developing a valuable mine.

(b) The applicant shall present sufficient evidence to show that there is a reasonable expectation that revenues from the sale of the coal shall exceed the cost of developing the mine and extracting, removing, transporting, and marketing the coal. The costs of development shall include the estimated cost of exercising environmental protection measures and suitably reclaiming the lands and complying with all applicable Federal and state laws and regulations.