My biggest profits have come from seeing or finding potential in a property that no one else sees and adding value to it, so depending on how far you want to take it, you could flip it to a builder for a quick profit once you show them it IS buildable, or if you have the experience or a partner who does, you can build on it and increase your profit.

Might want to see if they'll do it if you include a builder's risk policy until Unit B is finished.

By self-remodel, I mean, I am not a designer/engineer/builder/etc... by trade.

Is it go to have your buyer go with a builders preferred lender?

I've got posts of my STR experiences with rattlesnakes, prostitutes, intruders, more intruders, police, psychotic mutts, one tenant having an affair with another tenants wife, dead bodies, ghosts, wild animals, pellet guns, real guns, check cashing, marriage counseling, trips to the emergency room, drug overdoses, flat tires, kegorators, etc.

As an IICRC Certified MRS (Mold Removal Specialist), I can tell you quantities of mold like that can cause permanent damage to your body.

Builders and developers come to mind here, but this arguably applies to apartment syndicators as well as other types of investments.  

Often times you’re competing with buyers who are builders/rehabbers themselves.  

The builder put in a crummy bed in the upstairs master so we replaced it with a nice hospitality grade mattress.  

For anyone about to say that 50k is a unrealistic number, I am an owner builder, do most of the work myself and only hire out a few parts for the labor.