How does one compare the price between a sfh and a duplex with the same square footage, and finishes in the same neighborhood?

I don't believe in any of that- but when I was finishing the last unit in the evenings, there was definitely a ghoul about.

Sellers are attaining large surpluses at the moment due to the lack of supply in the town. 

Depending on the quality of the finish, the building size (the larger the size the lower the $/sqft), your level of experience, etc.

I’m clearly emotionally attached to this property but I feel like it’s gonna be a gold mine when the new development up the street is finished. 

That gets you a close up look at the level of finishes that are expected. 

Lack of ventilation is clearly causing your mold/mildew problem, so a functioning window will help, and the larger the opening the better.It does require a match on the exterior finish material to fill in the size difference, but these baths are always on the side or rear of the house, so it's not very noticeable.The fact that it's a different size and more contempo-looking than the older original windows, isn't a compromise on esthetics, either.

My name is Philip Wells and am originally from Buffalo but have relocated to Cleveland, Ohio after finishing my degree at Baldwin Wallace University.

I would finish the renovations and see about doing a cash out refinance or HELOC to use some of the equity in the Weymouth house toward a future deal. 

i.e. you might save 50k by doing it yourself, but it might cost you 2500 or 4500/month in lost Short Term Rents, so you'll 'lose' a lot by not finishing fast.Just some things to think about.