if so, about how much does that cost to initiate (ballpark)? 

Otherwise they will continue to pay yearly taxes and maintenance costs, and not be able to foreclose the property as it will sit here leaking and falling apart and the mold continuing to spread.

Costs?

I was able to get them $9,000 off of the asking price, and a $30,000 concession to cover closing costs and a rate buydown further increasing their cash flow.

To break even after commissions and closing costs, I'd need to sell for at least $275k.What would you do if you were in my situation?

BPCON will be rather costly, considering you need to fly to Mexico and the tickets start at $1739 if you are a pro member.

What's the acquisition cost, build out cost, exit strategy? 

If you could renovate and split off an ADU or even apply to turn it into a duplex or triplex (although that will cost plenty of money with new kitchens, utilities, etc.) that could very well be worth it.

On-site evaluations allow you to examine the property's condition, identify potential difficulties, and precisely estimate renovation costs.

taxes/insurance costs?