The Law of Purchasing Fruits from Non-Jews

What are the ways to purchase produce from non-Jews, considering it is forbidden to trade in it?

The commonly accepted solution according to the Chazon Ish is to appoint the seller as your agent to purchase the goods for you. Some sign an agency appointment document and appoint the seller in advance, while others are stringent and only order the goods from the non-Jew after the buyer has pre-ordered. Another solution is for the store to operate on a consignment basis, where the goods remain the property of the non-Jew until the customer purchases them, and if any goods remain or are spoiled, the loss is borne by the non-Jew.

The buyer writes an agency appointment in which he appoints the seller as his agent to purchase from the non-Jew [and the seller writes an additional agency appointment in which he appoints the agent as his agent to purchase from the non-Jew], and by this, there is no prohibition of trade in the purchase, because the goods are not bought from the seller [see Sukkah 39] but rather the expenses of the goods as they cost the seller and the fee for the effort, place, and losses of unsold goods are paid, and therefore there is also no prohibition of measurement and weight because it is only a clarification of the partners' shares who bought through an agent from the non-Jew. Some order from the non-Jew according to a list of clients, and then it appears more like a true agency. There are stores that sell on a 'consignment' basis, meaning the goods remain the property of the non-Jew, and the responsibility is on him. Thus, the payment goes directly to the non-Jew through the seller. Azmera Leshimcha (Shemita, Issue 2).