Powder post beetles and moisture problem

[Eric Jennings]

so I have a house under contract, this is for my primary residence in rock hill sc that I intend to house hack, and in my due diligence period the inspector found evidence of powder post beetles and extremely high moisture under the house and I'm wondering what this could end up costing me if i get it treated and have a vapor barrier put into the house and put up gutters to get this house to qualify for the loan and then it proves the damage is a lot deeper than inspected like into the sub floor i included some pictures to show the damage the inspector found 

still have a week and a half till my due diligence is up (2/26/19)

the really wet part is the beam at the front of the house around where the front door is