Quote from @Scott MacComb: I have had contractors just do a small list on a paper napkin, and some do something on a word document.

Paper napkin math says skinny deal. 

Cheers   Both cap rates and cost per door are back of napkin analysis to see where the current numbers line up.

Optimally, the lawyer or the firm should be familiar with public infrastructure that developers are typically asked to pay for, such as road widening, turning lanes, new roads, sanitary sewer extensions, new water and electric extensions, fire hydrants, etc.

I I am playing with different scenarios and want a back of the napkin number I will use https://www.omnicalculator.com/collections/real-estate.

Those napkin projections put it at 1 mil in 9 years though.

Don't use napkin math 'rules' to make investing decisions on.I hate the 1% rule, for the same reasons I hated the 2% rule a handful of years ago. 

You can figure out your income and expenses on the back of a napkin and pay down your mortgage faster.  

PLUMBING FIXTURESThe bathrooms, toilets and kitchen plumbing fixtures shall only be used for the purpose for which theywere designed or built; sweepings. rubbish bags. acids. sanitary napkins, baby wipes, paper towels.should all be disposed of in regular waste receptacles.

I mean like you said we don't all need white table cloths and linen napkins when we go eat..