Shell to finish out, cost guesstimate

[Donald Hendricks]

I found a duplex in shell only condition. This was a new build that stopped at the shell. Sewer is in place and plumbed through slab to main line. Inside is studs only. Needs everything, electric, plumbing rough & finish, HVAC, insulation, drywall, kitchen etc.

The roof is in new condition, windows are in place. Plumbing can be done at cost of parts as my brother is a master plumber and I get the family discount.

Please throw me some rough guesses as to cost to finish out from shell so that I can work some rough numbers to see if it is worth dragging a contractor out for a more definite $ amount.

I could guess at this repair or that for a simple rehab, but how to guess at this? Property is located in the San Antonio, TX area. Each side is 1100sf 3 bed 2 bath. This will be held as a rental in a working class neighborhood.

Let the flogging begin! Thanks for your input.