I would worry about the moisture causing dry rot.

It's susceptible to moisture and water, so not a good candidate for finishing.At some point, a previous owner decided to put a shower stall and a toilet in the basement.

3 bed 2.5 bath, ~1800 sfMajor exterior remodel due to that old nasty LP siding that swells and absorbs moisture.

The only sure way to remove any mold, does not matter on species, is to remove the moisture.

NOT AN APPRAISER - But usually they look at permanent fixtures (eg swimming pool) as an adjust to the comps used.However, if there is obvious major CapEx needed (eg roof with major holes and obvious moisture invasion issues) sometimes they'll take that into account, but they are NOT physical inspectors and don't know the cost.  

Then, once you treat/fix the problem, you just need to take some basic steps to prevent them from coming back (i.e. eliminate any areas of wood-to-ground contact, address any moisture issues, etc). 

Modern windows have Low E filtering built in, which reduces the amount of infrared light penetrating the window and the amount of interior heat / cooling that escapes.

@Donovan JamesHere is what I typically ask/look for in a house-Age of roof-Age of furnace-Age of water heater-is the electrical updated-Check for any major cracks in the foundation-If you are flipping the house see the age and condition of all windows-Check for moisture and mold in the basement-Check for any large cracks in walls-Check all ceilings for water marksYou may also be able to find a check list of things to check in a walkthrough on google.

Also pitchpockets for roof penetrations and disposal of the radiators and old boiler. 

Moisture / water / mold, knob & tube wiring, foundation issues, ancient plumbing, rust on the breaker panels, termite tunnels, powder post beetle damage, cedar post supports, improper footings, temporary lally columns, etc.As to writing an offer, that's a sensible and common approach.