Copper has chemical properties such that you can dissolve it, and then electrolyise it back out of solution ridiculously pure. More reactive metals stay in the solution, less reactive metals like gold, silver, cadmium and platinum form a nice little lump of sludge beneath your anode that's absolutely worth collecting.

It's valued per weight, like anything else. Wire will cost around as much as the copper inside does, plus a little for the cost of extruding and coating it.

TL;DR no, in the 21st century pure copper is just pure copper. If you make bronze then sure, there's many different kinds.