From personal experience with both stereo and guitar cables (especially guitar cables but yes, sometimes Tarzan, or someone who thought he was Tarzan, did swing from them) cheaper ones crap out on me. YMMV
Anyway, all I'm saying is that there may be some justification to spend more than $10 on a pair of interconnects and that sound quality might not be the only factor. Reliability may also come into play.
There may also be some difference in cable geometry or build material that can affect sound. I'm not saying it does or doesn't only that it may. However, I can't see how any wire, insulation, solder, jacks or whatever else goes into cable, can cost hundreds or even thousands of dollars.
The really expensive cable makers will tell you that "with some systems" the differences can be heard. In other words, if you don't hear any improvement with our cables, then your system really is kind of crappy. That being said, even if I spent $10,000 on my system I don't think I would spend proportionally more on my cables. Perhaps a little bit because I thought a certain cable looked cool and if I was spending more money on my rig, I would assume I had more disposable income.