With the equipment and materials often constituting far less than half of the total installed cost, even a 50% increase to get better quality wouldn't be that significant.
It's so much cheaper to pay a few hundred more on a furnace upfront and have it last 25-30 years instead of 15 with repairs required along the way.
I am not in the business of any trade I give advice on. I have non-professional hvac experience + good knowledge of theory. Attempt repairs at your own risk. Never jump out safeties - especially pressure switches - on a furnace for testing with fuel supply on; use a meter. Do not troubleshoot with live line voltage present unless there's no alternative.
Last edited by user_12345a; 07-30-2020 at 10:29 PM.