The Physics of Electricity

Can anyone explain clearly in either common parlance or technical terms the difference between a $1,000.00 cable and/or speaker wire versus a $20.00 (or so) one? What does wire "do" in an expensive cable/wire that an inexpensive cable/wire does not? Does it conduct more or "better" electricity?
There are plenty of cable manufacturers that will allow you to choose which cable will sound the best to you. Try them out in your home for 30 days and return them if you don't like them. You only end up paying for shipping both ways. It will save you aggravation from spending any amount on a cable that you are stuck with instead of enjoying. I did this with about ten different cables and chose the best one for my ears and my system. I'm glad that I went to all of the trouble. It was actually fun. Try it, you'll like it.
It just puts 980 more dollars into someones pocket!! That's all! God gave you a brain, use it!!!
About 20(?) years ago while purchasing a power amp, the dealer compared a few cables for me and my friend, not telling us the brands or price. We both agreed that one cable clearly sounded better. Turned out to be a Van den Hul.
Neither of us were/are audio experts, but we both greatly preferred the same cable with this amp.
My only point is, cables do sound different for whatever reason. Not sure price has much to do with it.
I'm like Nonoise. I pay what I believe gives me the most bang for my buck. Rok2id is fortunate where he can't hear a difference, so he doesn't need to spend money in that area. Same goes for having a boom-box or separates. You pay whatever amount necessary for what quality you want to hear.