The cost of a power pole transformer varies with its kVA rating, voltage class, insulation type, certifications and local market conditions. Small single phase distribution units used on residential poles are far less expensive than larger three phase units. Materials like copper and core steel, plus oil, bushings and accessories, strongly influence price. Utilities typically negotiate bulk purchase contracts rather than paying a single catalog price. Therefore, engineers usually talk about cost ranges and use budgetary estimates during planning, then seek firm quotes during detailed project design.