Now like magic that $22k roofing job turned into $12k-$14k. 

Unless y'all have an incredible W2 to help with the purchase, you will not find something that "works" in the Triangle and in a good/safe location.

Would it generally be a location that tends to have a higher cost of living? 

At over 4000 sq ft, I'm surprised you won't be able to list for a much higher number to net a decent profit, but without knowing more specifics on the house and location, I am speculating here. 

Your new place should turn into your new business location as well. 

How do you go about finding areas to invest in with limited capital?

I think $35 at the time of this writing and they can withdraw it and use it at other locations if they get denied.

Would need to know about locations of your buildings and current rents to see if there is anything that can be done now to get numbers a bit better.

As your portfolio starts to increase, you can start creating single-member LLCs where the property is located, and then you can put all these LLCs in a trust.

Where is your property located?