There are a couple of mechanical/electrical/plumbing items to be aware of in older houses.1.

I've confirmed the price by quoting with more than 3 plumbing companies and even the city came out to make sure it wasn't an issue on their side.

Replaced the main water line and all gas lines myself from the meters using YouTube tutorials and seeking advice from experts at local plumbing supply companies.

I had 11 of these and good systems in place but still had 1-2 evictions a year and 3-4 big things that were normal annoyances like plumbing leaks, damages from hurricanes, or some vandalism.

There is a 1st year bumper to bumper warranty,  2nd year plumbing and elec, and a 10 year structural. 

I am in the plumbing industry and all looks good.

Do you rip out all plumbing and electrical or just patch and fix?

New drywall, majority new electrical, new plumbing, ac unit, windows, doors, subfloors, bath, kitchen everything new.

Do you know how the outside plumbing is laid out? 

I need the drain and overflow replaced on a bath tub that is leaking into the basement in my rental property.  Access for the overflow is via a door in the closet.   I'm asking what a reasonable price would be for thi...