Agree. When it comes to that, if you already really want to store gold for bartering, you need to have something that is usual, and not really valuable.
What I mean instead of valuable coins you need to have cheap gold necklaces and rings.
It is much easier to find customer for 50$ ring then more valuable coins. And if you are in trouble, and need to bribe someone, you can offer “my grandmother ring” to someone, it is gonna be cheaper for you, and everybody likes gold, but not everyone know real value of some gold peace. So for most of the people golden coin is worth same like golden ring.
Everyone have “their grandmother ring”, but not too many have some rare coins.
Just have lot of cheaper golden pieces instead less (more valuable) golden pieces.