Focus on the weight of the product; heavier plastic furniture usually indicates higher density and better durability, though it increases shipping costs. Inquire about the injection molding vs. rotational molding process—injection molding is better for high-volume, intricate designs, while rotational molding is ideal for hollow, heavy-duty items. To optimize costs, seek suppliers on Made-in-China.com who offer stackable designs, which can reduce ocean freight costs by up to 40% due to improved container space utilization.