Additionally, and perhaps and even bigger factor, is that all QOZ real estate investments will involve either ground-up development or "substantial improvement". 

Not really your target respondent (not in major resort area), but I don't find it much additional work to list on ABB, along with VRBO/HA.

How do you decide how much of a discount is enough of a discount?

Additionally, finding the right investor focused RE agent will help you to analyze deals, keep you apprised of off market deals, and allows you to keep a pulse of the market conditions. 

Realtors keep advertising something along the lines of "Location Location Location WONT LAST INVESTORS DREAM", but this isn't selling.Some of them make me giggle a bit by offering a 10k discount off a 1 mil price as if that is going to do anything.

I don't know how to properly do the 'quoting' on this site but here's a few notable ones from Liesl:Jim,Thanks for sending the additional context for your question.

Tons of entertaining space in the basement in addition to the 5th bedroom and full bath.

Additionally I am reading and researching 2 hours per day about real estate  rehab costs, plus other related topics. 

Robert Clement - Does your lease have late fees listed as additional rent?

In addition, as you have alluded to these are often illegal units which means they will not be worth anything on the resale.