You ask a great question.
My experience has been that great-sounding speaker cables can be found at every price point: low $, medium $, high $ and truly insane $.
As a testimonial - My ARC Ref 6SE preamp now has 200+ hours on it, and as it has been braking-in, my low$ speaker cables have revealed everything nuance of the process... changes in tone, changes in staging, changes in attack, and the list goes-on.
Last night I was listening to one of my reference LPs (Imaginary Roads, William Ackerman WH-1078), this LP had a beauty and clarity that, in 20+ years of playing, had I had never experienced. It was a 'goose-bump' moment.
I am using AntiCables Level 3.1 (biwired). They reveal every change that I make upstream, and I do not hesitate to recommend them (even for systems costing tens-of-thousands of $).
An 8 ft. pair retails for $310. Anticables.com... I am a customer and have no business affiliation.