The faucet and plumbing was working OK.

They have maintenance contacts in every city and if you have an issue, you go online, explain the problem, and the plumbing company they contracted with for that city comes out, goes through the process and fixes the problem accordingly.

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.......

You may also want to inquiry as to whether your area has a Landlord briefing in which they explain the process and your obligations as a Landlord on the program, specific things to documents in your lease ( inspections, maintenance, laws to protect Victims of domestic Abuse and things of that nature.

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.