Clearly defined your goals will help much here.

But they complained before they got the letter, which clearly defined a reasonable material/labor cost for each item. 

If you hunker down into a specific community or area and commit to getting to know everything about the area, the sales activity, the rental comps, the time on market, the floorplan options (walk each one as they come on the market to get familiar with the flow of floorplans, and popularity of them based on time on market), it will make you a smarter investor so that when a property comes up within "your" community, you may have a leg up on an investor who is just doing broad strokes ARV estimating. 

As always, consult your RE attorney.Going the LLC route makes ownership stakes more clearly defined and offers liability protections but jeopardizes your above-stated goal of lower down payment.

@Brenden MitchumSo would it be fair to say that your formula is a 'back of the napkin' way to initially evaluate a MHP's broad based value?  

I think you really need to define what you’re looking for in rental properties, then you can start looking for the right city and the right submarket!

Maybe a PDF with defined line would be easier. but does your app take the CAP Expenses, maintenance, property management,insurance and etc. into consideration.

However, I’m not an economist and don’t know how broad of a conclusion we can actually draw from charts like these.

Seller financing is SO broad that it can consist of many different options, terms, etc... that a typical lender wouldn't consider and can usually end up being really beneficial to a buyer. 

Lot's of W2 workers looking for passive returns struggle with deciding which way to go, active, passive, self storage, multifamily, single families, ect.Once you have defined your criteria, then and only then should you start investing.