Are we talking about your own personal residence or your rehab/flip? I have a contractor I use for most of my work on both my personal and rehabs. I have time now to do some of the work in the rehab we just picked up but if I didn't I wouldn't hesitate to hire everything out.
As my business grows and I have multiple rehabs going at once then I won't have the time to be in there painting and whatnot. In order to pay contractors to do the work I REALLY have to focus on buying the property right so I can fit it in my budget.
Here is a list of the things that my contractor is doing right now on the project we are working on:
Power wash/paint exterior of the house
Build railing on the front porch
Drywall a bedroom approximately 10 X 16 feet
Replace a tub surround
Rebuild the chimney just from the roof up
Repair some drywall in garage
Replace two windows
Clean all carpets
Put down ceramic tile in a 8 X 8 utility room
Remove old fallen tree in the driveway
I think there are a few other things but I can't remember right now. I am getting all that for $2,400. It's going to take 2 of them just over 2 weeks to finish this. If I was to do it myself I would probably be talking about at least a month, plus with the painting and stuff that I am doing right now while they do that list above I would be looking at close to 2 months for a rehab.
So my point is... does it make sense to hire a contractor? Yes, sometimes.
Whew... that was a long one...