Give me a 10ft gold cable, then I'll believe it has anything more than a negligible effect on impedance.
and gold connectors on both ends and gold pcbs and solder...
My understanding (from memory of an electronics class a few years ago) is that gold is used for the connectors because it resists oxidation better. Copper is actually a better conductor of electricity.
For sure. corrosion just isn't a big problem for most consumer or home electronics though. Where it is, it's a problem in more than just the connectors, because most electronics aren't sealed. (it's especailly useless if the connectors on the $100 board aren't protected... and the $3 cable is..)