Are you sure you aren't getting quotes for a ground-sourced (AKA geo) heat pump? We just installed a 4.5 ton (overkill for your sqft) 20 seer unit for $18000.
Salesperson said there is excess demand for both labor and machinery for heat pump installations in the past few months. I wondered at the time to what extent this is a regional phenomenon (seattlites are nerds who like energy efficiency) vs. supply chain issues vs. a sales technique.
Interestingly, I learned that it will be too cold for heat pumps <10 days out of the year, so most people either keep their gas furnace as backup, or install an electric furnace for these rare days.
It's also the case that demand is huge.
I was interested in doing an air-source heat pump (because hey, my furnace was 19 years old and would have to be replaced soon anyway), but due to the excessive cost, the payback time was figured to be something like 50 years. I would have loved to do that, but it just doesn't make sense. Instead, it was new AC unit + new natural gas furnace.
Nevermind ground-source, which would have been much more expensive.
I am not sure I would pay $27k for the whole install, but once it's there I've found it to be great. Extremely inexpensive to run and with all of Seattle's power being carbon-neutral, totally guilt free to set it to 68F at night during a hot summer day.
https://freshchalk.com/greenwood-heating-air-conditioning-se...
May I ask where you are located (generally)?