One other option, that I have used in a situation where there was no commission offered by the Seller,  was to ask the investor to list with me on the subsequent sale of the flip property, and I made my commission then.

What we don't have are earthquakes, tornadoes, hurricanes, urban forest fires, slides, and tsunamis.

I've ended up discounting those gaps on a sliding scale. 

Then I realized I wasn't accounting for Property Taxes, needed to learn that, insurance, needed to learn that....and the even dreaded CAPEX, VACANCY, REPAIRS, PM dance we all love.All of those needed sliding percentages, so I can see to the top and bottom end FAST.I just have to reinforce what everyone is saying.

A mortgage lien and note are surely only one way to handle private money, especially when taking a loan from family / friends, or when a private money lender wants you to keep the loan out for subsequent flips. 

In my lease agreement, tenants are responsible to replace light bulbs as they go out.Some of them buy and put in LED bulbs, and when they slide the dimmer switch up and down, they either don't dim, or flicker. 

Some custodians charge fees on the sliding scale based on the size of your account. 

@Kristen Bouvier Scoville, if you want tax deferral from a 1031 then you want to have the LLC sell the property and subsequently the LLC will need to purchase the replacement property as well. 

IE tenant or subsequent buyer defaults causes huge damage and your now faced with negative cash flow for a year and 20k to fix the place. if you can handle that its okwhat happens though is you have unsophisticated sellers and in a lot of instances the home is lost to the bank and the sellers credit is trashed.. plus many times they want to buy something else and with this mortgage still in their name they cant.its just a very risky dangerous thing for a seller. 

Lending practices were drastically tightened after '08 which has subsequently lead to better underwriting and better debt securities.