My average vacancy across 7 years is less than .1% and numerous people I know are at zero vacancies across the same time period. 

Problem with most agents is that they simply don't understand investors and/or are not willing to write up numerous offers with investors in order to finally land the one that works.

There are numerous factors that play into the suitability of a lot, especially when the dimensions are tight.  

I am sure there are numerous variables that go into determining if the cost seg is worth the cost or not.

I reviewed numerous BiggerPockets forum posts and compiled all the recommended options for looking up potential sellers information.  

I was doing my little nosy  visit during construction and thankfully so because I discovered the day before the contractor was to start setting tile, the supplier gave them the WRONG TILE, and it was ugly tile too. 

I buy and hold long term, and have taken advantage of numerous  30 year loans at ~4% the last few years.

Unless you just really like gambling or have money to burn, in which case, by all means - roll the dice if that's your thing.Further - contractors and suppliers are SO damn busy these days with all of the construction going on around here that getting a renovation of any real scale completed correctly or a new construction job done is a very serious challenge in and of itself and takes a great degree of skill, care, TIME, connections, and probably some luck.

And its also a situation of putting all your eggs in one basket (versus taking the money and diversifying it into numerous passive syndication/crowdfunding deals).

They are either syndicators themselves, offer syndication mentoring\coaching, or interview numerous other syndicators.