National HVAC replacement costs average $5,000 to $15,000 per system lifespan

https://precisioneverydayhvac.tearosediner.net/staged-evaluation-determines-whether-fixing-or-replacing-makes-financial-sense-for-sacramento-homeowners

Most residential HVAC systems last 15 to 20 years, but replacement decisions hinge on cost-data benchmarks rather than age alone