I am inclined to agree, unless you're doing hi-fi recording, in which
case you might spend 200 bucks on a furman power conditioner if there's
something especially noisy in your neighborhood. But usually if
something is making noise on the power line, something isn't working
right, and the power company can be talked into at least looking at
it.I can't imagine what might be in the $1500 one that would make it
that much better.

I once saw triple shielded optical digital audio cable made by monster
in a fancy stereo shop.