The reason that chefs don't recommend the cooking sprays (Pam and the like), is that they leave a sticky residue on non-stick and cast iron pans. They recommend using oil (very little and wipe with a paper towel) or butter. On cast iron, swish the oil (very little) around bottom of pan and up the sides, wipe out with paper towel and heat to set oil You now have a "seasoned" cast iron pan.
I've been curious about the copper pans, but I have been buying cast iron instead. I have a set of Revere Ware (the original copper bottom pans) that dates back to 1948 and still going strong. Can't give them up! Also picked up a set of Caphalon pots at auction and absolutely love them.