Unique neighborhood and product within local market.

I'd recommend looking at costs. your build cost is going to be well over other homes because of the fixed costs like slab, Hvac, roof, etc. check the market drivers and weight the benefits of short term versus long term. long term is no furniture and help pays mortgage but at this size it doesn't really cover everything. we didn't find a lot of economies of scale in single family detached. can you build more than one unit?

or get good tenant for around 1200$ on vacant unit (i reduced rent from 1350 to 1200 as not much interest in current market) and hold few more years absorbing repair costs and contractor issues, trees issues, retention wall issues, tough neighbor issues, loud music, tobacco etc. smell issues, dogs barking issues.7.

Most can provide a rental report to see how much properties are renting for in your area and how long properties are staying on the market. 

There is no one size fits all answer for this question, market to market, and property to property are all different. 

An existing duplex provides immediate rental income and proven market comparables, reducing risk.

I’m brainstorming ideas on how I can market myself to potential mentors in the STR game in order to gain experience.

It justifies the property selling for greater than just market appreciationI do owner builder rehabs but sometimes use contractors for large work scope or scope beyond expertise.  

It's nice to hear from an investor who is doing the same thing in the same market. 

You could put most of your funds in the stock market and access them when needed for a HML.