No person engaged in the business of buying milk, cream, or butter fat shall, for the purpose of creating a monopoly, or to restrain trade, or to prevent or limit competition, or to destroy the business of a competitor, discriminate between different sections, localities, communities, or cities of this state, by purchasing such commodity at a higher price or rate in one locality than in another, after making due allowance for the difference in the actual costs of transportation from the locality of purchase to the locality of manufacture.