What happens when the customer does want to keep their old pipes? After all they are theirs and not the plumbers pipes.

I’m sure most people don’t care and are glad to get rid of what they see as junk and a hassle to dispose of.

I tend to keep things and build stuff (it’s a curse) so It would be hard to get it away from me. Over the winter I’m planning on building a good sized solar water heater out of salvaged copper pipes and other parts I have.

I was wondering if a person keeps the old item, do contractors quote a higher price? And do they make it verbally clear that they get the old parts, or do they wait till the end of the job and point out the contract was singed to allow them to take old parts?

It seems a little (lot) less then honest to do so.

Exactly. After the house was framed, wired and inspected I put soundproofing inside all the interior walls. IIRC the cheapest solution was R-13 Kraft backed insulation between the studs which worked out to about $100 per thousand square feet of living area.