Still mystified by mega expensive power cords

AC travels miles from the substation, enters my house, goes into a panel, then runs to my hifi equipment. Once inside the equipment it goes through whatever wiring the manufacturer used. I don't understand how the few feet from the outlet to the back of the gear can make some of the dramatic changes claim (low end goes down another octave, deeper wider soundstage, etc). My thought is that as long as the power cord is shielded so that it's not working like an antenna, properly grounded, and of sufficient guage so that you're not loosing juice to heat, and has contacts that make a solid connection, any power cable should sound like the next, especially since the AC coming in is rectified and smoothed.

I'm not looking for flames, but for those that believe in power cables, enlighten me. Or said another way, can that $11,000 plus power cable I saw today possiblet do more than fatten the manufacturer's wallet?