The cost for construction are not substantially different assuming that the studios are built next to each other and the plumbing is close.

As part of being a landlord you with sometimes encounter repairs that require the use of a skilled trades person, such as extensive electrical or plumbing repair. 

Our basement (where two bedrooms, a living room, laundry room and bathroom are located) has flooded several times due to plumbing issues.

I can do basic stuff like painting, plumbing, change out light fixtures, etc. 

This in Philadelphia.Moving forward I'd like to have a standard list of common plumbing issues bid on by plumbers. 

For those interested: The house is a 2bed 1bath with unfinished basement that is plumbed for additional full bath and room for additional bedroom in the basement.

Personally did significant renovations of all types including plumbing, window, drywall, kitchen and bath remodeling, ect..

I also want to start building a network of sub-contractors including electrical, plumbing, painter, and landscaper. 

Note: Over the course of the 10 years I've lived in and remodelled the house, I had to do all the work myself so I've accumulated a wealth of knowledge and tools about how to do wiring, plumbing, roofing, drywall, tile, cabinets, etc. 

Plumbing, electric, framing things out may be quicker to hire someone but being it is a live in flip I am assuming you are keeping for 2 years for the tax advantages?