And NO massive cold winter and no massive humidity and out of the thunderstorm belts.

Mold & mildew from high humidity?

When water gets past the window trim of these properties and starts to get into the designed air gap between the brick and the framing that the window trim covers, the excess water and the humidity attack the old mild steel ties coming out from the framed wall that keep the brick veneer attached to the wall.

If I manage to show that this is mold other humidity-related issues, how much can this reduce my purchasing price in my proposal?

Not to mention hot humid summers in the south. 

In North Idaho, we get hot temps for a max of 3 months a year so the unit is dormant most of the time and it never gets terribly hot. 97 was the hottest day so far this year with 30 percent humidity.

Worse...lowering the humidity in the house via dehumidification can draw MORE moisture in from underneath since moisture migrates from high to low. 

Our all electric Florida home has a/c on all summer to avoid humidity & mold & runs $85/month with HW tank off & no-one living there.

I don't care for Florida personally at all.. too hot and humid for year round living and too flat to many bugs etc.. we do a lot of work in Charleston SC I love that city and we are starting up in Charlotte as well.. the east side of the mountains look pretty cool in the Carolinas Asheville Greenville etc.. have not spent time there.. 

You will create mold and a high humidity environment throughout the home if not.