Elizabeth, in 2005 I posted;
To answer the original question, in general I believe you can get the job done pretty good at about 10 percent of system cost, and no higher than 25 percent. Beyond that, I would probably start replacing components or speakers.I just calculated the retail value of my system at around $50,000, of which the cables are about $4,000, or just about 8 percent. I have gone to DIY mostly made with high quality bulk cable and some of the best connectors available. I also have some DIY made with raw materials but, I generally like the bulk cable variety better. My only remaining manufactured cables are two Isoclean PC's I picked up with an amp purchase. In comparison, I do not believe the DIY cables are at all inferior to some of the better manufactured cables I have tried, by Cardas, Purist, Acoustic Zen, Harmonic Technology, Audioquest and others (no, I haven't tried them all). I still believe the bigger bang for your buck is in the components and speakers, and would allocate maybe 10 to 15 percent for cables, and another 5 to 10 percent for isolation and room treatment. Of course, buying used and DIY can reduce those numbers.