When we sold our house, we found an agent who was also his own broker. We paid him $500 and he did exactly this. Gave us the forms, put the house in the MLS showing a buyer-side 3% commission, and then made a note that we were representing ourselves and we listed our phone number to call if you wanted to show it. I think we signed something saying he wasn't representing us too.

We had our house listed with a REALTOR for about 2 years prior to that (keep in mind this is during the market crash). But within about 2 months on our own, the house sold.