The applicant for registration shall pay a fee as follows:
a. On or before July 1, 2020, six hundred dollars for each pesticide proposed to be registered, provided that the applicant has submitted to the department proof in the form of a federal income tax return for the previous year showing gross annual sales, for federal income tax purposes, of three million five hundred thousand dollars or less;
b. On or before July 1, 2020, for all others, six hundred twenty dollars for each pesticide proposed to be registered;
c. After July 1, 2020, fifty dollars for each pesticide proposed to be registered.