On average, most USPS-approved commercial mailbox systems cost between $1,000 and $3,000 per unit, depending on the size, mounting type, and required parcel lockers. Homeowners, business owners, builders, and developers install column-mounted mailboxes to complement a property's architecture and provide easy mail retrieval. Rather than opt for traditional mailbox and post designs, they install preformed column mailboxes or column mailbox inserts set into. Distribution box cost encompasses various factors that influence the overall investment in electrical distribution systems. A distribution box serves as a crucial component in electrical installations, housing circuit breakers, fuses, and other protective devices that ensure safe power distribution. The industry leader in the manufacturing and distribution of quality commercial mailboxes and residential mailboxes, Salsbury Industries is officially licensed by the USPS to manufacture Cluster Box Units (CBU's). Smaller wall-mounted units with just a few compartments can start near $100, while. At Mailbox Directs, we sell durable, highly secure cluster mailbox units (CBUs) that your customers or tenants can rely on for their mail.