If everything was fixed up and the seller is cash flowing nicely, he can just sit on the market waiting for a full price offer, but with half his units not being rented, he can be in the hole or barely breaking even (depending how much he is getting for the other two units).

Not the "quick key" special ones with the tiny hole and special tool, those can be easily broken, but the more standard ones.

Of course, I don't know Fulton from a hole in the ground so I could be completely wrong.

I lost out on a duplex in the Kingfield neighborhood because I had a verbal commitment on my offer but by the time I had a formal offer written up (and was in the hole $450 to an attorney) the seller backed out.

I got sucked into a black hole of Googling on Tuesday, and found this forum.

From (AOAA-Assignment of Agreement Addendum) outlines the details of Partial Assignment, Total Assignment, Assignee's Name, etc. and a section where you check a box stating that Seller has been advised that Buyer IS or IS NOT receiving monetary consideration from Assignee for the Assignment.

With regards to electric: 20 amp GFCI protected outlets at kitchen & bath counter levels, hard wired smoke/carbon detectors 15' from all bedrooms and 1 on each level, grounded outlets (if the outlet plug has 3 holes typically your all good if not you will be pulling new wire), from your general comments on overall condition you will likely be looking at a new service & panel as well.

One thing we're doing is focusing on how to add non-monetary value add for our sellers.  

I walked into the unit and to my surprise, I found yellow stains and a big hole in the ceiling of the living room.

Landlord here: I've a new tenant moving in next week and during the walk-through he points out some minor issues on the walls in two of the rooms (previous tenant hung pictures so there's some pin holes and marks on the paint).