Is it considered unlawful gain to falsely claim a higher offer for a product in order to achieve greater profit?

The seller must be truthful in his sale and not lie, so that blessings may be bestowed. If he lies, he obliterates them. The seller's statement that he was offered a certain amount for the merchandise, while he is lying, is consuming wealth unlawfully and deceiving, and it is akin to the forbidden practice of najsh, where he increases the price to deceive the buyer. If it becomes clear that the seller is a liar, the buyer has the right to annul the contract or agree to a partial refund.