Any public entity, as defined in Section 1100, including any school district or community college district, when purchasing food, shall give preference to United States-grown produce and United States-processed foods when there is a choice and it is economically feasible to do so. For purposes of this section, the determination of “economically feasible” shall be made by the purchasing public entity, considering the total cost, quantity, and quality of the food and the budget and policies of the entity.