HiFi tuning Foo-uses

How can fuses possibly make a difference? I'm in no way an expensive cable believer, but I do think you need to find something fit for purpose. A fuse is basically a few mm of thin tin wire, so how and why do these sell, and for so much! [TL: moderating comment: it is the firm view of pink fish media that all electrical equipment should be run with the correct fuses installed according to the manufacturer's recommendation. This thread should be read with that in mind.]