(I'm in a place where Chinese IME is not available)

Fang has less expense because of his geological location: San Diego, where it is not hot in summer and not cold in winter, so no AC needed (vs Los Angeles Valley area).

I don't know my number but I am sure it is a lot. I am interested in your geothermal setup.

(Don't know if Fang also has geothermal at home)
If it is not a new house built with geothermal already, meaning you'd have to introduce geothermal to your existing house (after your purchase), how much does it cost (from where you are, I assume not California), for how long and how much (digging) work to be done?
(As much as you know)
Thanks!