Mobile Home Park Analysis-What am I missing?

[Jim Bray]

Hi BP family! Jim here.  

This is my first forum post. I just went PRO and am learning to analyze properties. 

I took a look all over the country and ran into this Mobile Home Park.  I used the BP "Buy and Hold" calculator and tried my best to be conservative.  Obviously, having not seen inside the units I can't know exactly how much repair.  I did see it needs a new septic system and used the most expensive estimate I could find online.  I then added 15,000 more for unforeseen rehab.  Even if I did a lot more, it still seems like it would math out. I'm almost certain that my first attempt would miss something but I can't see what yet.  

https://www.biggerpockets.com/calculators/shared/1714497/58c84ecb-b699-4d66-ae10-66b6bab74085

PLEASE help me grow my education and savvy on these strategies!  THANK YOU ALL!