I suspect a $6 binding post is a perfectly good quality binding post. A Cardas binding post is 10x the cost. It should sound better. For me $15k is a large sum of money to spend on an audio component, but in today's market it won't buy SOTA parts.
Did I Expect too much?
I purchased a pair of speakers from a US manufacturer who I shall not name. The speakers are beautiful and the sound exceeds my expectations (after a minor upgrade). So why would such a reputable company use six dollar binding posts? It makes no sense. I replaced them with Cardas binding posts and decent 12 gauge wire between the driver and posts. My system is valued for clarity and clean highs. The difference was audible. I know, snake oil. But it wasn’t. I don’t think that spending $15K for speakers is nothing. So yes, I was disappointed.