Lots of us. Begin now vetting mold remediators, their licenses, insurance, references, emphasis on the references that you can actually get on the phone. DON'T diy this. What you will find from the responses or posts from the past here is that you can get a handle on this. It's your initial "unknown" that's the real hurdle. As you interview prospects you WILL see who's top notch and who's okay. As you talk this through with them you will begin to see what they are doing. The vacant house has had almost no air exchange plus no dehumidification in the form of regular air conditioning. Add to that old, leaky windows, humid basements, crawl spaces, leaky roofs, and you have elevated humidity in a food-rich environment, where mold is concerned. Tell your remediator that your goal is to find the source of moisture. Is it only no HVAC? Quite possibly. Is it the lack of gutters combined with poor grading, quite possibly. Is it the plastic sheet under the slab is ineffective, maybe. I bet someone from your neck of the woods will have a name of a company that prices their work to fit into investment paradigms. How many square feet is it? Most states allow diy for a certain small amount. BUT, good testing is VALUABLE! from a reputable remediator. So test! I hope this helps!