If you have a lot of time to burn then you can save pennies on some things... but the time spent shopping pretty quickly zeroes out the cost savings.

I have tenants that left the heat off while out of town and the copper froze and split in 5 different places.

I think Matty covers this as well.As for why gold, why not copper, lead, etc, you have a point.

It’s to bad, but it sounds like from the feedback getting most good contractors are priced out of working with investors who are mostly looking to pinch pennies.

In the process she had a quick look inside and discovered the place had been totally trashed, all the copper was gone, graffiti on walls and ceiling, toilets ripped out, faeces and urine everywhere.

Other scenarios where not having permits can come back and bite is when something is clearly done that isn't code like a finished basement with one exit, bx is used openly instead of copper wiring in conduit, finished attic or dormers, or enclosed porch.

Although we aren't zillionaires by now, with a portfolio of hundreds of properties that cash flow and appreciate, without having put a penny down, we haven't failed.

once again the money in RE does NOT come from a paltery few hundred dollars a month cash flow, a late fee here and there or a few pennys saved by managing your own property. 

I know this is an expensive upgrade, but if the house has old copper pipes, I would upgrade to pvc.

For example, there are costs associated with wall damage, overgrown lawns, hard wood floor damage (both buff + coat and sand + coat), missing smoke detectors, etc.