Listen to your dealer, especially if he/she will allow a no obligation home demo.
Those who say cables/wires make no difference just haven’t experienced a meaningful difference in their system or they can’t understand why a specific cable might make a difference so they deny it without trying. Doesn’t much matter to me why.
It may because their setup didn’t need the help, couldn’t exploit the help or that cables truly make no difference. It also depends on the electronics, the length of cables, etc, etc. Blanket statements are frequently incorrect be they from the evangelist or the atheist. Try for yourself because there are alot of factors at play. Your room, your power, your electronics, your speakers, your preferences tonally...don’t be afraid to try and if you don’t hear a meaningful improvement, it doesn’t mean that cables don’t make a difference, it just means you don’t need what that particular brand/model brings to the table. BUT, if someone is telling you that cables don’t make a difference for your system they are incorrect and have an agenda, pro or con. It defies logic that they are denying what you may or may not be experiencing in your room with your gear.