New roof, new ceiling, upgraded appliances, spray foam insulation in the crawlspace, added a heater to the crawl space etc... 

A male will spray and every day additional damage piles up.  

The other agreed and suggested that I at least have the inside sprayed so that it would be appealing to an investor.  

The reality is that changing a lightbulb, or the smoke alarm batteries, spraying a little WD-40 on a squeaky hinge or things of that nature to not necessarily constitute adding value.  

I would consider having the siding sprayed, or if you are ambitious, roll/brush it out yourself.

Hi Chris,A good couple of cans of Kilz aerosol spray (flat) will cover that stain.

Can you just gut the unit and then spray everything with a chemical to kill the mold?

I feel like its fairly simple--spray the ceiling w/ some water and scrape down the texture. then skim where you need to and paint it flatI ask bc I've gotten 4 quotes:-$500 to scrape and skim if needed-$400 to scrape and up to $300 to finish/skim-$1750 to scrape and skim 2 coates-$1375 to scrape and skim Such a huge gap. is there enough to mess up here that i'd need to pay over $700 for 865' of ceiling to scrape and skim?

I called an exterminator and he said typical spray won't handle it. 

Does this mean hiring a pest control company or does this mean by something like RAID at the store and spraying it everywhere?