The top 10% of surgical techs earn over $68,000 per year, while entry-level and uncertified techs may earn around $27,000. Certified technologists can expect to earn more.
There are several factors a home warranty company may consider while determining if the covered HVAC system should be replaced or repaired. If repairs of the system will cost in excess of 50% of the price of a new system of similar type, they may advise the replacement of the system.
The home warranty costs $600/year, so if we pay for the home warranty for the next 10 years and the furnace/central air unit goes during that time (which I expect it will), the warranty has paid for itself while giving us some extra piece of mind on the unknown issues in the rest of the house.