Hvac contractor advice
I am currently planning a 4700 sq ft house with an additional 1500-2000 sq ft basement to be finished in the future. My builder's hvac guy recommends two 3-ton units GSHP (1 for 2nd floor and 1 for first and basement) with 4 zones for $70,000 with drilling ($18,000 included in the price). On the other hand, I went out and received a quote from a much larger hvac company that also does a lot of geothermals with a proposal for two units (one 3-ton unit for the 2nd floor and one 4-ton unit for the basement and first floor) and also 4 zones with a price of $58,000 ($13,000 for drilling).
Both companies are using climate master tranquility 30 and all the duct work and Honeywell thermostats. Both are doing 150 ft per ton drilling. The cheaper proposal actually already includes the desuperheater and buffer tank.
My question is:
It's really no brainier that I should choose the larger company with cheaper prices, right?
Is it common for a buyer to choose his own hvac guy instead of the builders "go to guy" for that big of a price difference?
My builder is a very reputable guy in my area and is very well known. He seems to be a very honest guy, but he prefers to work with someone he knows and he "can be sure they are doing it correctly".
Please help, appreciate any advice