Newbie Investor: tempted to pull the trigger on this

[Zoi Zeo]

Hello.  I recently came a cross a duplex (list price $229,000) currently rented (1st: $1000, 2nd: $1100).  Owner says they'd consider owner financing, however, during my walk through one of the apartments had what looks like black mold around every vent.  The deal is As-is condition.  Both are two bedrooms 1 bath units.  

Numbers i put together was $5,000 down with $215000 owner financing (rate TBD).  The numbers and rates I used give me a $250 - $350 cash flow positive per month.  I was alright with these numbers until I saw the mold.

Anyone have any thoughts around this type of mold issue?  Looking around 5 vents in the unit all with black mold around them.

Appreciate any feedback.  This would be my first deal.