The price is primarily driven by the Rated Current (A) and Breaking Capacity (kA). For industrial applications, ensure the box supports high breaking capacities (e.g., 50kA or 100kA) to handle short-circuit currents safely. The Enclosure Material also significantly impacts cost; Stainless Steel (304/316) or Fiberglass Reinforced Polyester (GRP) are more expensive but essential for corrosive environments, whereas Cold-Rolled Steel with Powder Coating is cost-effective for standard indoor use. Additionally, verify the IP Rating (e.g., IP65 or IP66) for dust and water protection.