And maybe you will be lucky and find that rare gem of a person who does really good work and will work for peanuts.  

I did driving for dollars the other day and found a place that seemed like a gem in Pasadena, CA.

Any stone you turn will find a gem under it.We're located here in Roseville and would be glad to support your needs and lend a helping hand if needed.Good luck,Randy

When acquiring these old gems, or objective is to improve their energy efficiency by a minimum of 50% (40% on newer, post War houses) while updating the building to provide modern, healthy living spaces for our tenants.  

That discount as well as the vintage of the loans insulates the fund, in a sense, from fluctuation in market rates rising and falling.There is a correlation to investor desired returns and prevailing market interest rates and returns however in general the closer you are to market returns via market interest the more sensitive the investment would be to rate movement.  

Of course you can find some gems that way, but is it worth your time to do so as opposed to finding deals via MLS, Craigslist, bandit signs, etc.

One benefit of direct MLS access is the many filters I can use in different combinations in order to find hidden gems.  

It's funny that sometimes the properties that look the best on the internet end up showing terrible in person and the ones that don't look as good on the internet end up being gems.  

New condo-like rentals with amenities will likely rent at a premium to your vintage two flat.

That said, you could try finding a smaller/larger home of similar vintage that sold within the past ~year in that neighborhood and figure out the square foot price.