You have to go beyond the range of just offering up numbers, you need to provide verifiable math behind it. 

Remember when purchasing a SFH with the intent of some day renting you must do the math before you buy.

would require you to have some "skin in the game", ie. a down payment.. also, they might charge points upfront..The biggest complaint I've seen (on BP at least) is that HM lenders won't 'approve' the house you're wanting to buy, and it ends up costing you an 'appraisal fee' or something..My biggest advice when looking for HM Lenders is DO YOUR HOMEWORK !! 

For some numbers:Purchase price $5,000 (seller paid for the transfer)I sold for $9,900Buyer put $5,500 down and paid for transfer (I paid $80 for a duplicate title because I made the mistake to have it snail mailed)Buyer has a lien on the title.Buyer has payments of $137 a month at 10%BUT the buyer did not want that payment although she could afford it by the math.  

Can you show me the math?  

Cash will probably be tight; but, I trust my math and her eye so if those two things make sense I am confident we can get the deal funded.

I'm not that good with RE Math and all the Alphabet symbols that you guys use to evaluate a particular property, but, you can look on Zillow at the Zestimate graph for properties in S.

The buy low sell high math is or could be the most profitable part and it just vanished with some turnkeys. 

The purpose is to present the scenario in as concise and simple way possible so that the focus is on the math problem and not relationship between characters.

In the future just ask your real question up front: "How do I convince a money partner that cheap unspecialized labor costs more than expensive specialized labor'The answer is to just use math; find out how long and how much it would cost to bring in an electrician/etc.