Gold connectors on a Toslink cable really is audio jewelry. You can at least make the case for gold on an RCA/coax out as it will not oxidize, but on an optical cable no signal is running thru the metal part anyway.
I would be a little leery of the ultra cheapo optical cables that are as thin as #2 pencil lead, if for no other reason that durability. I've had some very cheap (like $5) toslink that were almost as thick as Monster Cable, and I've used Monster's toslink, too. I can't say it was any better- in fact, for a fairly cheap cable I'd say that AR toslinks are constructed virtually as well for about 1/2 the price.
As for why a person would pay more- a Yugo will get you to the same place as a BMW will, so why do people pay >$60,000 for a car? Mostly the same reason for both.