If you trust the sponsor and the strategy aligns with your goals and objectives they can be a great investment vehicle. 

Set your rates to meet your objectives over a 3 year time frame.  

There's nothing wrong with choosing to rent at a rate they can afford in order to help them if that is your primary objective.

Also, equity building at the expense of cashflow should not be an objective of yours if you're new.

Just want a fair price for his share and the way the discussion have gone, I'm looking for a little ammo or objective formula to use to simply it all.  

If you are considering making a proposal that is structured as a purchase with and without owner carry, each scenario should meet the aforementioned criteria, that is a deal that produces a satisfactory return that also meets the Seller's objectives.

Make sure your refinancing terms align with your long-term cash flow objectives.

No system is perfect, so don't waste your time chasing after the next shiny object.

This narrows down the options and helps investors focus on properties that align with their objectives.

It looks like they used a sharp object to hit the tub in two places.