So, to me its more of a "value by comparison."

When comparing how much a house might sell for in a neighborhood after rehab, do I compare it to houses in that zip code, or do I compare it to the houses immediately surrounding it?

To combat that risk, hard money loans typically come with higher down payments and higher interest rates in comparison to traditional loans.

As a percentage comparison, pending sales continue to climb faster than new listings coming to market.

I personally did the comparison myself and for my situation (I got 2.25% on my FHA loan with ~82% LTV), my MIP won't need to be paid after the 11th year and I would come out ahead financially in all scenarios (in the beginning because I put less than 25% down, and in the end because my monthly payments would be lower for 19 out of 30 years due to the eliminated MIP after the 11th year).

My point is that the market as a whole shouldn't be your comparison, but rather compare to other listings in your local market.

If other area duplexes are going for around $76K the % of monthly rental yield is going to be greatly different for you at $150K purchase by comparison- an mount to which trying to make up for in rent rates would outprice you on the high end from your competition. 

Although income taxes are high in NYC and properties are expensive, property taxes are quite low in comparison to asset value.

What are the STR for the different islands of Hawaii? I see that Oahu basically requires you to be in one of a limited list of properties or condo buildings. Are the other islands similar? 

The area, the block, features like SQFT, beds/baths in comparison to other homes in the area, your marketing, your response and response time and on and on and on.