HVAC replacement price and scope cannot be reduced to one reliable national price. The useful comparison is the written scope: diagnostic work, exact equipment or component identity, access, compatible parts, labor, refrigerant handling when applicable, electrical or duct corrections, permits, commissioning, warranty terms and disposal. A low headline figure and a complete installed scope are not the same product.
Inventory every connected indoor and outdoor unit, thermostat, duct concern, electrical or fuel connection, drain, access route, and comfort objective before comparing proposals. Equipment selection is only one part of replacement because design, distribution, controls, utilities, removal, access, permitting, and commissioning can be separate work. A contractor can evaluate heating and cooling loads, system matching, ducts or other distribution, electrical and fuel requirements, drainage, controls, and installation constraints. Ask for an itemized scope naming equipment, design assumptions, modifications, permits, removal, startup and testing, documentation, exclusions, and warranties. Climate design, construction practices, utility service, jurisdictional rules, labor and equipment supply, and site access make replacement scope location-dependent.