Then scale up to flipping some of your best deals that come your way.

If the operating partner does flips a lot, he could own his/her partnership interest through an S Corp, if he/she has scaled that far. 

I've seen guys scale at a property a month, and others stumble for over a year before committing to an offer. 

This is a large scale BRRR project.

Just not on a huge scale.

I owned a duplex in Ferndale (a trendy inner-ring suburb of Detroit) from 2005-2018, and intermittently lived in part and rented it, so I have experience on a small scale with finding tenants and managing a residential property. 

I think most investors who really want to scale get to where they eventually start looking outside of their current market! 

The reason for the gap between entry level tract and million-dollar custom builds is that outside of the large scale developers, construction costs range from $150(rock bottom)-450(luxury) per square foot with 250 being about the price you can expect to pay for basic builder-grade finishes.

They have already stated that they want to repeal the new corporate tax cuts which could be enough to tip the economic scales and start the downward slide. 

That's why you only really see SFR (highest prices) and large MFR (big economies of scale) getting build. $80k all-in sounds VERY cheap for a duplex, even when you're doing a bunch of the work yourself.