When negotiating you are seeking the highest price possible while the buyer is seeking the lowest. The way a real estate agent's commission is structured does not encourage them to get you the best price — an extra $20,000 means a lot to you, but it can be as little as $400 extra commission for the agent. 
win-win negotiation settlement is an integrative negotiated agreement. In theory this means the negotiating parties have reached an agreement after fully taking into account each others' interests, such that the agreement cannot be improved upon further by any other agreement.

Make it simple for a buyer, provide them with all the information they require to make an informed decision.