Quote from @Diana Palavra: My specific questions for experienced flippers:The Process: Do you rely on your own "napkin math" to estimate repairs during the initial showing, submit the offer, and then bring in contractors for hard quotes during the inspection period?

Again — this is very back-of-the-napkin math.

Consult a real expert who does a thorough comparison, not some useless quick estimate on a napkin.

Two tips: start with a simple back‑of‑napkin cash flow to decide if a deal is worth deeper work, then layer your detailed spreadsheet only on the top few.

I find that when it starts to slip, it usually gets worse.Operation, Maintenance, Storage, Alterations to Premises: On a continuing basis, tenant agrees to: Keep premises in a clean, neat, and sanitary condition; no parking, storage, or accumulation of debris on lawn or yard.

Good thing I remember a little from thermodynamics classes and have AI run some back of the napkin math to see how big of a warm wate plume 1.2 million gallons per day will make.

1% is a rough guideline for napkin math.

Simple napkin-math shows financing at Ryan's purchase price just under 70%; par for the course in commercial real estate. 

These generally don't require as much infrastructure from the county (septic instead of sanitary sewer, usually no stormwater systems required), and I sell them to consumers wishing to build their own homes on enough acreage to have vegetable gardens, chicken coops, etc.

I see it every day with folks running deals by me that when I do simple napkin math they dont come close to working..