priority mail cost box refers to the cost associated with shipping packages using USPS Priority Mail and utilizing the USPS Priority Mail boxes. The price of shipping through Priority Mail depends on the size of the box, the weight of the package, and the destination. USPS offers several flat-rate boxes for Priority Mail, where the shipping cost remains the same regardless of the weight or destination, as long as it fits within the specified size limits. Some of the most common flat-rate boxes include the Small Flat Rate Box, Medium Flat Rate Box, and Large Flat Rate Box. Additionally, USPS also offers non-flat-rate Priority Mail options based on weight and distance, which can be more cost-effective for heavier items or longer distances. Priority Mail also includes benefits like free tracking, delivery updates, and insurance coverage for lost or damaged items.