The market seams to be slowing down and I fear I've missed my window but my renters are just now moving out and I need to do some repairs on the place.

- add central air or replace window a/c?

They go nowhere (they are just a metal box with charcoal filter and a fan, and there are no windows in the bathrooms. 

The agent had my dad's brother come to the property to quote the previous homeowner on replacing all the windows, and after the homeowner realized the cost of fully rehabbing his home he decided to sell as-is. 

Given that it's a smaller office space, you might put a sign in the window and put a listing on Craigslist.

It has been updated quite extensively since 2013, including 2 new refrigerators, new windows upstairs, complete remodel of 1 unit, and a new roof in 2015.

Hallway was sloped 2" from side to side so there was definitely structure or foundation issues, all the tenants smoked so saying there was a lingering smell of smoke is beyond an understatement, walls were literally orange and caked with cigarette smoke as was the soffit outside two windows, multiple broken windows, peeling paint, doors stuck shut from wear and tear, broken front doors, and the worst part was every tenant knew his name and addressed him as if they were old pals (big problem).

Value means all modern appliances, efficient HVAC, dual pane replacement windows, 200A service, washer/dryer, etc. 

Have them look at everything, especially the major cost items like the foundation, structural integrity, the plumbing, the roof, and the windows. 

I originally used google docs on my phone to take down addresses that had unkept grass, bad/ old windows, just an ugly or rundown appearance and anything with notices on the doors or windows.