All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Both buying and selling should be based on sincerity, clarity, and not lying, cheating or deceiving. Hence, it is not a sign of sincerity for the seller to use a pseudo name or invent a false story in order to promote his goods, because this is lying, deceiving and cheating, and these are even more forbidden in selling.
Therefore, if you want to start a business, then you should start it with sincerity and truthfulness and inform the customers of the real condition of the goods so that Allaah may bless your business.
As regards returning the goods if they are not in conformity with its description (provided by the seller) or that there is a deficiency in the sold goods, or that the buyer conditioned a condition that is not available in the goods, then the buyer has the right to return the goods to the seller, and there are some rulings about this but this is not the place to clarify them.
Allaah Knows best.