Black mold has a white ring around its outer circle. Mildew, is very often mistakin for black mold. I know the difference...do I tell my customers that it's only mildew?? Not on your life. Infact, I generally add a zero when it's mistakingly diagnosed a black mold situation.
I never got sick. I smoke cigarrettes and drink a pot of coffee a day...so if there ever is a respitory problem, what caused it?
If you do have black mold, rip out the dry wall, saturate the studs with bleach(two coats), put new board up. You'll be just fine.
JMHO
SR
I may be reading this entirely wrong, but it seemed to me that you are saying that you raise the price if people aren't informed enough to know the difference between black mold and other molds or mildews. Is this what I'm reading?