Suppose you could place an amp and speaker so that the terminals on the amp touched the terminals on the speaker. No wires at all. Would this not be the perfect setup? As good as it could get, no wire at all, and what some wire makers strive to achieve. I'm speaking in generalities here, no wire in particular, inside, outside, whichever. But it is impractical to place your amp and the speaker cone touching each other, so a length of wire is needed. Any change in sound that occurs once you've introduced a length of wire is strictly less than the no wire senerio. It cannot create anything new in the signal, it can only subtract. So, designing wires is strictly a subtractive process, what frequencies will be reduced more than the others? What effect will capacitance, inductance and resistance have on the sound? These are the properties of the wire that would not be there if things were perfect, And the amp was connected directly to the speaker with no wire. So, wire companies do research, and experiment with different metals and materials to see just what will happen. What subtraction will have the most pleasing sound. Remember, wires cannot make sound, they cannot add anything to the presentation. Only subtract. The materials that wires are made from are not inherently expensive, so the bulk of the money spent on them is to pay the researchers for their time, and intellect. Whether you think the price asked is worth their time and intellect is completely subjective. To each his own.