The price is primarily driven by the core material (gypsum, fiber cement, or calcium silicate) and the thickness of the boards (typically 9mm to 15mm). For high-traffic or specialized areas, you must specify fire-rated (Class A), moisture-resistant (green board), or acoustic-insulated properties, as these can increase the unit price by 20-40%. Additionally, the gauge and zinc coating (GSM) of the galvanized steel studs are critical; thinner steel may be cheaper but compromises structural integrity.