He hired a mold remediation company and looks like there is significant amount of mold and the cost estimate to remediate is coming to 12k. 

These were all have to be corrected and remediated by the buyer with all permits. 

In the meantime the neighbor got my phone number from his landlord and texted me about the spray paint on his car to which I responded that my contractor is responsible and will remedy the situation.

I would try to remedy with the tenant and say something like, "oops, looks like you overpaid for a couple of extra weeks...I'll be returning this to you as our lease ends 7/15 so a full months rent isn't necessary to carry us to that point."

I've seen lead remediation costs under $1k and I've also seen them above $40k.

@Benjamin SulkaThis one was mostly cosmetic: paint, carpet/floors, light fixtures, trim, landscape clean up, rodent remediation, bathroom vanities in the 1/2 baths, and some of the windows.Rehabbed one unit at the time aside from the windows.

If the property can be sold, pursue a short sale for its current value whatever that may be after considering the cost to remedy these issues. 

@Yashar Fred most of the items a housing authority identifies as deficient should be remediated anyway.  

The wholesaler can then try to obtain any remedy provided for in the contract, usually enforcing specific performance.  

We categorize the problems into two groups:Deal Killers (or Deep Discounts): These include complete system failures, such as needing a new well or septic system, which significantly impact the bottom line.Deal Modifiers (or Small Repairs): These are minor repairs like hydrojetting the drain field, installing a new riser, repairing baffles, or replacing pumps/tanks, which can leverage a lower offer.Step 3: Making the Final OfferWe make our final offer only after a full system evaluation with remedies.