And I've finally made the jump to a, "bigger building" I'm feeling good about the price, the location, the documents I'm getting from the seller. 

In other words, I see the short term value in niche, but I would never want to become so niche that if I wanted to sell in 10 years I might be pigeon holing myself

My goal is to build up a strong portfolio of long term rental properties that will generate cash flow which I intend to use for reinvestment in the short to medium term, and to enhance my retirement cash flow in the long term.

Or, have him seller-finance until you can get the permitting resolved. 

Milwaukee has not been easy to BRRRR for the last 3 years: with ultra low inventory sellers just did not have a need to give a discount for condition.

Purchased various sheriff auctions, short sale, and just low balling.

In the past there were more options to get creative with seller financing etc to put down less than that, but now the primary lender in general won't allow this as they want to assure you have sufficient skin in the game.

I am not a seasoned investor, but I have learned a lot in my short time. 

Eg if doing a short term rental, don't assume it will be rented all of the time.What do the numbers look like if you took that money and bought a home as a rental?

I am a newer investor (currently 1 short-term rental in addition to my primary residence) looking to purchase a property that I will make into a short-term rental.