@Elliot Lamson, on the surface of it, your Realtor is acting as YOUR buying Agent for this deal, right (or have I misunderstood)?

They could be as simple as just requiring surface injection by epoxy or could be major. 

If you have an experience regarding buying and holding in a similar fashion I would love to hear about it!

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

Yea the buyer bought the property, but not in a timely fashion because of the tenants, which was a breach in the original agreement, which = no $$$, but I was able to help out a person and man did I learn a lot along the way. 

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.

You are the one that puts deals together in a win-win-win fashion for all parties.