There may be someone that would partner with you for a pre-determined equity split.NOT LEGAL OR TAX ADVICE:  You will probably want to form an entity to purchase in that spells out the equity / ownership splits and lays out exit strategies. 

✍️For example:The typical project often has the sponsor providing investors with a “preferred return,” often in the 6%-10% range, before the sponsor gets any proceeds outside of returns on his own personal invested capital and a predetermined split, say “70/30”.

Monthly utility and routine maintenance costs can be your responsibility while you live there but I'd suggest having a pre-determined 'move-out' date.

Bottom line isn’t whether you agree or disagree; the articles reasoning, methodology and conclusions are predetermined and biased, so the article is beyond useless.  

In most cases there is a portion of the monthly payments that are applied to the principal/down payment, the rest of which is paid at a pre-determined closing date. 

Bank A will have a spread (basis) of say 150 while Bank B may have 250 - - so the answer is "you can't predetermine what you will find".

@Bob Bowling Bob, he is a turnkey seller who will present move-in ready properties at predetermined prices.

That may test your friendship, so predetermining it early will help mitigate any bad feelings because you agreed and put it on paper.I would also recommend adjusting your splits on a deal by deal basis. 

As I understand it it is similar to a land contract where the deed stays with the seller until the contract is paid or some predetermined time in the future.

I'd like a contract to be as clear as possible so clients can plug and play. aon the GC side changes are pre-determined mark-up on materials 15% (surcharge 15% also for removed scope, and +15% material handling fee/markup), then labor rates are pre-determined also 55/hr electrician/plumber 45/hr painter, etc.