How do I know if seller is selling genuine cables?

Agree that the only way to be sure is to have the cables verified by the manufacturer. I once bought a pair of Audience Au-24 i/cs that looked to be genuine. When I went to re-sell, Audience contacted me because mine appeared to be very similar to counterfeit cables that they had seen before. I had a lengthy and pleasant email exchange w John MacDonald, the owner and ultimately he offered to verify them at no charge. So I guess the answer is to buy from a reputable seller w the understanding that you have the right to return if the manufacturer says they are not genuine.

Listen to 'em if they sound right LOL!

Fake cables might sound good too, that doesn't mean that you want them.
You could buy from me if I had anything to sell. I don't at the moment. That would be a guarantee. My cables are not fakes unless they are made so well that even the manufacturer missed it.

Only buy from persons with many killer feedback then pray.

"So I guess the answer is to buy from a reputable seller w the understanding that you have the right to return if the manufacturer says they are not genuine."

Wouldn't the obvious sub par sound tell you it's a fake?