Mary -
It's very common here to base the commission on the price less any seller contribution.
In our MLS we place the sales price in one field and have a "seller concession" field as well.
Most of our broker/agents notify the company representing the buyer at the time of negotiations that commission will not be based on the full offer price. Since it's a common practice in our area, there usually is not an issue.
Debbie DiFonzo, e-PRO, GRI
Broker/Officer
United Country VIP Realty
Vice-President Lebanon Board of Realtors
Lebanon, MO 417-532-2031
www.ucmissouri.com
Marshfield, MO 417-468-5900
www.uctheozarks.com