I'm using a Monster subwoofer cable in my system right now on one of my subs. I bought it years ago (1998) when I got my first sub, so it was around in the box when I added my second SVS a couple of years ago. My first SVS is connected with a Better Cable that I bought from SVS at the same time. Can I tell a difference? No. Did I expect to? Absolutely not.
The Better Cable end connectors are nicer and the cable is more flexible, so I like it better. It actually cost more than the Monster cable, though, so probably not what you're asking. I've also used Monoprice cables (not on my sub) and other inexpensive cables (on my sub), and no - I can't tell a difference in audio reproduction.
Monster isn't bad cable, it's just overpriced for what you get if you pay retail. Get a good deal on them, and there's no reason not to buy them. I admit that I don't get the allure of BJC. They always seemed overly expensive to me when I'd go look, and a member here (Barry) sent one of their HDMI cables along with something that he sold me. I have to say, I wasn't impressed. Didn't seem built better than others that I've bought for about $5. Doesn't mean it isn't built better, but because the digital signal works fine with my inexpensive cables, the only thing that would make me want to buy them is if the connectors were easier to install or if the cable felt better or routed better - that's not the case with the cable that I got. So, I'll just continue to save my money.