Although its true higher priced brand wire isn't any better, it can be worse.
Two~three years ago I was setting up a stereo system in an extra BR. I needed both banana plugs and wire, so I went to RS as I like their banana plugs. They had a short roll of Monster XP that has a center dielectric, said to improve the highs. So I got it.
Now I was hooking up speakers I've had for years, so I knew exactly how they should sound.
The result was the highs sounded very harsh, so much for improved highs!
I orded some BJC 12 awg, hooked it up and all was good again.