Junction box installation costs $100 to $300 for parts and labor, depending on the installation location, accessibility, and the electrical box size, material, and indoor or outdoor rating. The distribution box cost encompasses not only the initial purchase. Buying an underground power installation typically falls within a broad cost range, driven by trenching length, permit requirements, and local rates. The price is influenced by distance from the utility connection, trench depth, and whether road crossing or tree/landscape protection is needed. In that case, we usually send you a quote containing the street light junction box price list.