However, I can give you 3 Core The Knowledge Base, and the 2 Golden Rules I use with no deviation:Golden Rule #1:  Never under any circumstances, ever, for any reason or rational, ever...SPEND your own cash/money.  

My point is, you can get silly creative in a way to rationalize to the IRS, lenders, etc. that everything is on the up-and-up but it's still a misrepresentation of your intentions and (therefore) fraud.  

Talk to active flippers in your neighborhood and ask them what they ended up paying for rehab on their last few deals.This back of napkin stuff will still have huge margins of error though, so ultimately you will need to make the lowest offers you can negotiate and back those offers up with some sort of rationalization for them to ever be accepted.

Because the survival instinct will always win out over the rational brain & our elders continue to pass on our younger generations will, as a method of "connecting" hold on to   more & more stuff going forward.  

The "secret sauce" is to memorize this sequence of numbers, 1073741824, and follow the 2 Golden Rules of Real Estate Investing:Golden Rule #1:  Never, under any circumstances, or rationalization, ever...spend your cash. 

But think about rationally.

The answers to these questions matter to understand the rational.

I am confused as to how to select a turnkey company on a rational ROI basis.

This statement means nothing...unless your plan is to rationalize a bad deal by saying "I could get $175k...maybe"

Not even looking at the numbers themselves or the rational I would have not gone further myself.