Are wearing/buying/sellings reps haram Reps are replicas like replica clothing, perfumes bags etc. There is good money in selling these and is that permissible if I let the customer know its a replica

Selling, buying, or wearing items that carry a fake brand name or logo is not allowed, even if you tell the buyer, because it violates the brand owner's right and helps in that. An item that only looks similar, with no brand name or logo on it, is a different matter.