This requires knowing how to build a team to rehab and manage the project & carries a lot more variability & risk.

Or even what not to do with him....it’s too many variables.

There are so many other variables to consider that far outweigh the rate. 

Some of the variables that come into play include structural rigidity, plumbing and electrical integrity, current mold damage, etc.

For a rental I think it is fine.In regards to the front door there are a few variables. 1-Is it a historic district?

However, for a US citizen, I'd conservatively assume 70% (or even 60%) if it's not a foreclosure.For the interest rate, it depends whether it's fixed or variable. variable rates are obviously cheaper and can be sub 2% or even sub 1% at times.

I owned one in a flood aone for 10 years and it can zap cash flow and it is a future variable you can't control. 

FAST4. in the above scenario, operators are often trying to offset/overcome the above variables with risky rent growth assumptions in the 6=% rate annually, and this is a dangerous assumption.There is only so many levers to pull and push.  

As to accurate inputs, there are a ton of variables that will be property specific.  

Areas around downtown are variable between B- and D.