I'm particularly interested in an inexpensive, horrible sounding power cable to try in my rig, to see if I can hear any difference at all.
Okay, but wait a minute. Didn't you just build your own DIY power cord? So is the problem you can't hear any difference? Or you want to see if there's one even more horrible sounding?
Serious question. Because it seems you use a lot of your own DIY cables. And seriously, the last guy I knew who did that, he had so many of these horrible sounding cables it got to the point he truly could not hear any difference between cables, until he brought one over and tried it in mine. He was shocked how easy it was to hear the differences, and how obviously inferior his money saving masterpiece was.
Also I don't see why its necessary even to ask. Every audiophile worth his salt has a drawer full of horrible sounding power cables- they include em with every component! If you have ANY power cords, DIY or otherwise, that don't make those freebies sound horrible by comparison, well then that's your problem right there.