We have a provision in our lease that states the tenant is to keep the home in a neat, clean, and sanitary condition.

Now, using VERY simple back of the napkin math; if you stuck to this plan and average $100 profit per door per month, you'd have 127 units earning you $12,700 per month, or $152,400 per year before taxes.

Now, if I back of napkin, $200/sq ft to build, this would give a cost of $200K/ 1000sq ft unit, and 12 units on the parcel.

Just napkin estimates. 

House is not kept up to any sanitary standard.

I actually asked for the last 2 years of P&L statements and essentially received the last 12 months of income/expenses written on a napkin.

You do not want something on a "napkin" you want an itemized line by line cost broken down material  & labor.

When she had company, she tore the paper plates in half and the napkins in half and washed the plastic forks for reuse.

It bragged that the property backed up to "government land".There's lots of government land around here: BLM, National Grasslands, National Forest, State Forest, National Monument, State Parks.......So I took a look to see what government land.The property backs up to the Sanitary Landfill.

Items such as food scraps, cotton balls, q-tips, paper towels, napkins, feminine hygiene products and diapers are not to be flushed down the toilets.