I have some of the CCC magnet wire here from Vampire and when I listened to it (straight wire bypass test) years ago I thought it sounded rolled off. They use two layers of "Red Soldron".....whatever the heck that is. Anyway, too thick of plastic for me. I asked Vampire if they could get it with a single coating of the purest, thinnest poly they could but they said they couldn't....only could get the red soldron stuff. Cardas magnet wire suffers the same problem.....way too thick of coating (2 layer, I believe) on the individual strands. Seems they think the wire has to withstand several thousand volts.....very silly. If you are going to use litz with high voltage....then just put some cotton or silk over it.
Yes, copper prices keep going up. I was interpolating from their site and also the prices of PCOCC on the Canadian Take Five Audio site.