A little background info:  My father in law is about to have his condo foreclosed on.  It is currently in forbearance and in about 6 weeks he will lose his property according to him.  I've just learned of his situation about a day ago.  He has come to terms with it, and is saying that he doesn't have enough time to sell the property, so he is planning to just walk away from it.  The condo is in Chicago suburbs.  He paid around $330k for it 12 years ago, and zillow is "estimating" that it is worth about $350k now.  I'm estimating that he has about $100-120k of equity built up that he is literally going to abandon if he doesn't do something quickly.  On top of losing this money, he will also destroy his credit (he's already lived through a bankruptcy once, and is ok with the idea of doing it again).  Sadly, he has brought this whole situation on himself.  He has been gainfully employed for over 5 years as a manager of a country club.  As covid ramped up earlier this year and there was an eviction ban, he thought he could just get away with not paying his mortgage.

I made a half-serious suggestion to him that I would buy his property from him for exactly what he owes the bank (in cash), that way he could at least save his credit.  He was very interested in my offer.  I guess if I was to proceed with the thought experiment, I would then sell the property immediately at market value and hopefully make about $100k.  This is obviously something he could have done himself if he wasn't terrible with his finances. 

Personal relationships aside - he doesn't maintain a very close relationship with his daughter or our family - what could go wrong here?

Before closing, i would get an appraisal of the property to know approximately what my market value is.  I would also have a title search done to make sure he doesn't have a 2nd mortgage, home quity loans, or mechanical liens, etc...

Thanks in advance for your insights!