It will be much cheaper to fix than to demo and having it does add value.

I just finished the guest bathroom (just putting up fresh tile around the tub) and tonight, I will start the demo in the master bathroom (shower). 

For my area that would be high unless the property was real low priced (A piece of land for 15K, a low end mobile home, a house falling down that will require a cash buyer who wants to demo it).

@David Zheng Just found a live animal trap in an attic of a house we're doing demo on.

Demo, finish work, etc can easily be done by you.  

For instance, when doing a rehab you often come across conditions that need to be addressed that simply cannot be seen or known until you start demo work and disassembling the current home.

Previous sub only did the demo and disappeared.

Some companies have a not very obvious clause of tacking on an extra 10% for demo if needed.

All good after week 1 and no real surprises......always the most tenuous part when demo starts and what will be uncovered. 

Im not too worried about the demo work.