Would the additional 3% accrue to future years, until cash flow is able to pay it out or a refinance catches it up?

@Dennis Weber  out of sheer curiosity... is his a closing attorney you speak of ? 

Out of curiosity, have any investors thought seriously about how the population drop predicted by people like Elon Musk will affect the real estate market?

Straight split 80/20 or 85/154. 12-14% annualized returns with 6-7% of it being offered as a pref and then the remainder accrues until sale/refi and is made whole before the GP gets to participate in the refi/sale proceeds*Sponsors who have switched from one structure to another, how did your investors receive it?

Marks mortgage payment would be around $2600 per month, leaving $1,150 in total cash flow per month or $13,800 per year or a 13.8% ROI before taxes.Mark also accrues equity against his loan principal balance per year of around $10,000, giving him a total ROI of $23,800 before taxes.

Generally, the accrued equity that has built up within the option period through the tenant buyer is of little concern, can't be capitalized on?

Out of curiosity, where would be a good place to start learning the REI math. 

You must know exactly when the interest begins accruing, and you must pay the card off at that time.

Assuming that the convoluted insurance/repair issue doesn’t give the buyer a legal out for breach by the seller, the seller can file foreclosure and collect the total due, including late fees, accruing interest, etc.If the buyer is okay with letting the property go, and if the seller agrees, he can simply deed the property back to the seller using a Deed In Lieu.

OK, curiosity aside, man are you behind the eight ball here.