If you can see mold anywhere, there’s likely more hidden mold, like inside the walls, the HVAC system, the attic etc. If you’re at all serious about this house, get an inspection by a mold remediation specialist. It’s nothing to fool around with. I had some mold growth in the ceiling of an apartment for 2 years, and it made me so sensitive I could no longer eat cheese, yogurt or mushrooms without feeling sick. It took many years to get over that.