We have recently purchased a 14,000 sp. Ft metal bldg. for rental property. The plumbing pipes must be changed out and the city permits one of the following: Galvanized, Cooper or a Flexable product. We have received quotes from 2 plumbing companies. One using galvanized pipe ($10.000.) and the other using cooper ($13,000). Please advise us. We will own this property for 15 + yrs.
Thank You,
Debra

If by "Flexable" you mean PEX tubing, then I'd go with the PEX tubing.

Plumbing in this day and age with galvanized piping would be an anachronism, and I can't believe people are still using it.

Copper, of course, is a great product, but you can have the job done for far less money if you use PEX.

iamgrowler is right on, copper is my 1st choice, would never use galvanized unless its in an area that may take some abuse like in a shop. Pex is the easiest and less costly and dyi friendly.