I just hope their RCA's are better then, Colin! I'm not expecting world class performance from them, but hopefully I'll get some decent bang per buck.
I'm having to homebrew some better mains cables for myself as well, again I'm not expecting earth shattering performance. I couldn't resist some pirate grade oyaide lookalikes for the ends (I've started calling them "No-yaides"...) Hopefully, these ends, combined with shielded mains cable and MK toughplugs (which my friend will print lifters for to make them easy to pull out of the sockets) or some "easy plugs" will give a reasonable step up from basic cables.
That said, I also quite fancy the idea of flat braiding some mains cables, for the heck of it. Who knows?