What is the ruling regarding a perfume seller who uses a specific bottle designated for selling to perfume himself or his customers?

If a customer purchases perfumes, they buy them on the premise that they are new, unopened, and unused. This is a recognized customary condition. It is not permissible for a perfume seller to sell a bottle of perfume that has been used to scent customers as if it were new. Rather, he must inform the buyer that it has been opened and a portion of its contents consumed.