@J Scott wrote a book on rehabbing costs and it is an excellent resource to have on your shelf.

With BRRRR, you get your money back, and the c-o-c becomes infinite (if positive), since you have $0 in the deal.

Pay cash, refi your money out, infinite returns lol.

If you don't have savings for a down payment/ repairs you will find it infinitely harder to get started.

ROI: Infinite (no money in the deal!) 

With low owner occupier financing the cash on cash returns can almost be infinite, so you will also want to include gross rent multiple analysis as well--how many multiples of the purchase price are in-place or estimated annual gross rents?

@Jonathan Stastny There are a million tools off the shelf, but none built for your business model exactly.

However, I see this almost as a pension or annuity for investors because after all capital is returned through a refinance, the investors still retain the same ownership so at this point, the investors have an infinite cash on cash return until we sell, which hopefully is not for a long time.

@Nikki Beall There is an infinite amount of stuff to read or watch regarding REI. 

I'll slip the surly bonds on traditional investing, dance on the silvered wing of infinite CoC return, and touch the face of no money, no skills, and three hours of work per year real estate investing.