An option to purchase could be a duplex to house hack, this can help you bring in extra income, and/or if it needs rehabbed you can live in the property while you do the rehab. 

Years of contemplating ways of making extra money outside of my day-to-day job.

The appraisal is usually issued for the benefit of the lender so you can play hardball and share that the lender will not release a copy of the report until after settlement (which does happen in some instances depending on the lender and their policies).

It’s a way to “sneak” extra funds in to your retirement account.

The usual ones, like business and economics, always work.

The money I pay in rent for the extra time is offset as soon as I am in the quadplex for 16 months. 

(assuming because that's what that price would most likely get you) How much extra cash would you recommend having on hand AFTER buying the duplex?

100 percent. there usually is a solution, often the best opportunities arise from seeming ominous challenges\

I look in to them often, but the story is usually the same….”there’s a reason it’s being wholesaled and not on the market”, and it’s usually not a good one lol.

An expert like @Dave Foster could tell you if there’s anyway to pull it off if you have the extra 50% in cash laying around.