Mobile Home Valuation help

[Eliot M.]

Found a MHP in my area that I'm interested in.  This would be my first so I really need help on analysis and due diligence.  Here are their financials for last 3 years, with specifics taken out to protect the innocent.

71 lots, 45 TOH's.  So only lot rent.  Lot rents seem low at an average of $111, but I will confirm this during due diligence.  

The 60 or 70 GRM that I've been seeing repeatedly would impute a value of $300k but they are asking $700k.

One thing that pops out is there are no provisions for on-premise manager.  The owner/agent tells me this is because all tenants send only lot rent and there is no need for management except for the occasional drive through done by the owner.  This seems too good to be true and I would like to bake in an entry in my own pro forma for management.  What should I put for management?

Also from my research it seems like 40% expense ratio seems average. These financials would imply an 8% for this particular property. Should I just ignore the 8% and make my own pro forma to have 40% and base my own valuation off that? At that expense ratio, a 10 cap would impute a value of $350k, in the ballpark of my calc using GRM above.

These would all need to be confirmed during due diligence, but assuming the above are all validated, I wouldn't pay more than $350k for this property.  What do you think?