Don’t give that discount to the customer. Offer it first to the sales associate.
WHY?It’s often an effective way of moving merchandise, and it protects your reputation as a store that doesn’t like to do discounts.
HOW?Determine the minimum you would accept for the item then tell the staff that if they sell it above this price they keep the difference. If you aren't comfortable with creating an environment where team members may fight over the sale then set up a collective fund in which all staff can share.