If you take two comparable homes of equal quality, condition, age, features and location but differing sizes, the smaller home will invariably show a higher value for $/sq ft.That number is somewhat useful in a development where there are cookie-cutter homes that are identical in every way, but unless the development is new, some will have been upgraded and/or updated and others will not.Your best bet is to get contractors in to bid on both a gut rehab and a tear down. 

If you bought 5 identical units for $500K then each one of the units would have a basis of $100K. 

I am capable of changing the name on the agreement if it's a single member LLC and I'm creating another identical one for a different property.

They were scammed by someone who stole the identity of our company and represented himself as me.

If I find a house that is identical to mine, except for flooring and countertops, then I want to update the countertops, how would I know how much of the price differential comes from countertops versus flooring?

Email is NOT secure, and you will expose your contractors to unnecessary risk of identity theft.

The guy calls me back, mostly because he was shocked and frankly concerned, because he is the sort of investor who has gone to great lengths to hide his identity from everyone for all the typical reasons.

@Kalen JordanNot all deals are created equal, and not all operators do things identically.

The idea is that once two properties are found that are identical to each other, with exception to a single element, be it the number of bedrooms or location or whatever element it happens to be, that the difference in price between the two properties can be attributed to the one differing element.So for example.

It is identical in terms of weather and ocean/coastline and a wonderful area.