Surface mold can often be effectively cleaned off non-porous surfaces.

The issue is that poorly conceived, written and originated options that attempt to be creative or require any performance by the optionee, will not be a valid option and then defaults to an installment sale bringing Dodd_frank to the surface.

If you're going to install or upgrade windows, it makes no sense to go cheap - - install eGlass.eGlass is two or three panes with a special coating on the surface between the panes and only on the pane facing the interior of the room. 

I'm Sure many others will weigh in on this as well, but on the surface, it looks like you may have a potential deal on your hands.  

Once those older systems no longer see daily use and sit for years many die off.You need to review the condo budget and see if there have been pluses or losses the last 5 years and if the board is constantly changing over ( instability ).If it is in a bathroom then without a fan could be surface moisture.

The actual surface is very smooth.

The important part is to prevent warmer, moister air from traveling to cooler surfaces where it will condense.

It lives on surfaces outdoors, and gets picked up in the air and blown around.

The topic of disclosure requirements for agents engaged in wholesaling surfaces every now and again, but there definitely seems to be a lot of confusion on the subject.

The REI education school I'm connected with has a two-day on-line tax and legal class which only breaks the surface - the tax code is many thousands of pages!