Here's the problem:
On the one hand, bad cables can ruin a recording. Good connections, quality cable construction, etc. is important.
On the other hand, lost of folks out there are selling snake oil. Cables can sell for more than a pair of Schoeps tubes, and that's a waste on money.
Get a cable that transfers signal & has a good tight conenction, and don't buy anything you can't return after listening to it.
-Noah