I understand traditionally banks will go off of COST/PURCHASE PRICE if it is lower, but maybe others have experience / suggestions. 

It’s important to not repeat the mistakes of that era but unfortunately we are not addressing some key problems.One of the key problems is the inability to perform the same level of due diligence as traditional channels.  

If the chimney is not essential (i.e. no boiler or furnace using it) block, disable (and down the road remove) it - chimneys, particularly those with traditional fire places, are major sources of heat loss.   

I have been researching wraps and sub to's and am starting to understand them but am still unsure if or what can be done when there is no traditional mortgage and it will be completely owner financed.

The traditional residential conveyancer may simply not have the experience, clout, or relationships to pull this off.  

I've been a traditional investor (stock market).

I've yet to dive in on commercial, however I'm stating now my goal is to own a commercial property in the  next 5 years.I've got a couple banks lined up that should work with me once I reach 4 traditionally financed residential properties and would continue to loan indefinitely as long as the deal makes sense.Trying to get creative at the moment to make my equity work for me - have probably focused too much on debt paydown and with cheap money for now need to get focused on acquisition mode -- believe there are still some opportunities for single family in the $120-160k range here.  

There are tons of methods out there than the traditional methods you are currently utilizing if you are up for it.

In addition it traditional takes just as much time and effort on my part to purchase, quote, rehab, resell, close a house that should net 15K or 25K.

I want to buy and hold mostly fixer uppers but not do the traditional renters but more of renting to buy for individuals who cant currently qualify for a loan but dreamed of being a home owner.