My area is quite unique, constantly improving and almost recession proof due to proximity to big apple.  

Agreed that you need to get 3 prices and a clear scope of work among the 3 (apples to apples).  

My point is, you can not compare apples to oranges.

They are like apples and oranges, so I'd bet we can make this thread more valuable by being specific :-)

This is a  "Subject-to" transaction, hopefully using two notes.A seller is willing to take I/O for 20 years is probably 1 in a thousand and they will be taxed just as Greg is, make that 1 in 10,000.I'd bet Greg doesn't mention the other issues with a Sub-to, foreclosure, Greg can only foreclose on his interest, that could be paid off, the note to the first seller is pretty worthless, that can end up going to the state in a medical issue, then there are risks of bankruptcy, law suits by other parties, collections and servicing, deed transfers, insurance, liens and the list goes on, which is why you should not do long term subject-to deals.      

Is there a better metric besides those two to compare two properties apples to apples?

Apples and oranges.  

One of the larger ones is Apple Inc.

I have to be able to compare apples to apples.

Then get comps on the rentals in the area, again make sure you are comparing eggs to eggs not to apples.