Gold is useful for preventing corrosion on copper contacts. Generally the point of such cables is to have a long useful life in a variety of conditions. If you're a touring musician, the cables will be subjected to wide temperatures, humidity (beer and soda!), and physical abuse. The "best" cable is one that is well constructed, has durable connectors, and yes, a corrosion-resistant plating can help prevent problems due to contamination or corrosion on the plugs and sockets. But coatings can be physically worn off and scratched. Don't place too much value on precious metal coating...
There are vast amounts of "audio foolery" (aka "marketing wank") out there. Most companies want you to believe that their cables are best. It's only fair in a competitive market. However, pseudoscience and irrelevant jargon are sometimes employed (along with massive price increases). Thanks to the placebo effect and various cognitive biases, people can actually think such products are better, thus perpetuating myths and rip-offs.
As long as the signal gets to the next device in the chain without perceptible modifications or losses that exceed the noise floor or transformative nature of said device, it's sufficient. In other words, you will see a much larger difference changing amplifiers than you will changing conductor type. Using a silver stranded cable might have lower resistance than a copper one, but if the amplifier you're using is introducing artifacts and noise particular to its design, there's very little point in delivering an extremely marginally higher voltage to it.
There are other considerations such as capacitance and inductance based on the construction of the cable. For example, a cable with high capacitance will act like a filter and attenuate higher frequencies; conductor type is only one factor.
If you only follow the marketing hype, you'll pay a premium price for something that might not perceptively improve anything, or at worst introduces more problems because of bad design. (You could argue that a device or cable that noticeably alters an audio signal in some way is perceived as "better" by some people, because they like having some frequencies rolled off, but that's a discussion about subjective opinions.)
Look for a cable of reasonable price from a reputable brand. If audio quality is your primary concern, obtain an expensive cable and have someone randomly swap it with a basic one. If you can reliably (better than chance) tell the difference in a blind test, then please report back!
