How much does it cost to replace an HVAC system?

A complete HVAC replacement (furnace + AC + coil + thermostat) costs $5,000 on the low end for a basic 2-ton split system in an affordable market, $7,500 for a typical 3-ton mid-tier setup with standard ductwork, and $12,500+ for a 4–5 ton high-efficiency variable-speed system in a high-cost metro.