@Jake August just with a bit of quick back of the napkin math, it looks like the park you are referring to has an average rent per pad of $600 per month. 

Heck, you could sell your house on a bar napkin if you wanted to, but you would lack a lot of legal clarity around what happens in this or that situation. 

I have only done some back of the napkin analysis but it looks like it is cheaper to buy land and develop my own 4 unit as opposed to paying for an existing property and then having to spend thousands to improve it.

I found a manager who I am using that managed one of the comps as well and did a back-of-the-napkin analysis with them as well which confirmed my projections.

Tenant shall not dispose of any substances or materials that may cause clogging, damage, or deterioration of the plumbing system, such as grease, oil, hair, sanitary products, paper towels, wipes, or chemicals.

What is the property's suitability for septic or proximity to sanitary sewer lines?

As well as possibly find a sanitary drain.

That’s about where I would back of the napkin it too.

The Animal must be properly cared for with no offensive odors emanating from the Rental unit, and proper sanitary conditions must be maintained within the unit.

The 1% rule, while a good back of the napkin approach, completely ignores price appreciation which is the single biggest driver of returns in Metro Phoenix.