OTOH, plumbing materials cost very little vs. the labor.I've had bids that vary by a factor of six for labor for the same job.Its very difficult to come up with any rules of thumb for this.

I know what my worst-case costs are if something like a major plumbing or electrical problem comes up, so I know the worst-case scenario if I miss something and I'm always comfortable with that worst-case scenario.

Being a master carpenter when we purchased the home I completely gutted it to the frame and rebuilt it as if it was an actual house.New plumbing, sub-floors, ceramic floors throughout.

But I didn't want to dig through the concrete to deal with the plumbing.

It would not be a fancy shower unit, just plumb a second valve and head in, possibly bigger hot water tank.Ultimate goal is to add value.......

Lets say for example you go to look at a prospective house to buy and you notice that the plumbing is in poor shape, if you have worked with your plumber in the past you will know how easy or difficult this task will be to accomplish.

I have a plumbing issue that has made the washer connection and kitchen inoperable due to clogged line.

New AC plumbing and other items installed, drywall starts tomorrow, and it looks like it will finally warm up enough to shoot the pool plaster!

I paid about 10k in repair costs this year for a new HVAC and the basement had to be excavated due to the plumbing collapsing under the house.

Large properties bring large logistics, management, and I learned to really hate clearing toilet and plumbing lines, you would not believe the things those people tried to flush....