For the HiFiBerry DAC I was looking for gold-plated RCA connectors. Unfortunately they are hard to source. But finally I got a pair. They are from a well-known manufacture and from a well-known distributor. They are not fakes.
Have a look at it:
The outer contact is gold-plated and the inner contact has still a normal nickel-surface. There is nothing wrong with nickel contacts. They usually work well. However, if the ground contact is gold-plated, I would expect also the other contact to be gold-plated. Looking at the manufacturer specs, it says “gold ground shell plating”. These connectors are purely made for devices that should look expensive. I guess, there are many devices out there with these or similar connectors.