I'm not sure what the renovation cost would be to set this up for a rental.

There are some scenarios which can change the equation and take priority over the opportunity cost equation demonstrated above.  

In addition to the workmanship, you want to work with someone who is good at managing time, people and his relationship with you, his client :-)    We are actually building out a network of approved contractors because one of the biggest pain points investors and landlords face in Philly is finding reliable solutions. 

Obviously aside from minor material cost savings the biggest reason is to save labor on all of the cutting in, which I feel would likely be moot with 3 sheens.

Need advice from more experienced self-managed landlords.

I find that they actually offer more than some other programs at a fraction of the cost. 

Quote from @Luis Guerra: Your management cost is 10%? 

@Andrew GarrettI’ve been investing in NC for a while, the main issue with Raleigh is rents are low compared to costs of homes.

In Milwaukee, I'd need 2 exits from the attic and 50% of the space has to have at least a 7 foot height on ceilings.Two things you want to check: both requirements are correct, but on top of that the city is getting reluctant permitting 3rd units: 50% more occupants mean 50% more water and sewer and 50% more traffic and parking.The other issue is that the cost of finishing a thrid floor with proper insulation/ventilation will run about $50-60/sf and only makes sense if you can get strong rents. 

Find a trusted and experience agent/lender/property manager, then start your property search.