I have received quotes to install a new furnace and A/C unit at our
house and wanted to get a sanity check on the price.

The load calc indicates a need for a 120,000 BTU unit and a 4 ton A/C.
The units would replace a 120,000 BTU that was original to the house
(1982) and a 3 1/2 ton A/C that was also original to the house
(1982). Since the house was built, there is an additional 300 sf or
so, with a total of almost 3,300 sf of space.