Ask them what their fee is, and recognize that it's negotiable. That doesn't mean that every agent is wiling to negotiate their fee. Some agents value their time (and their buyer) higher than others... but that doesn't mean you can't try.
Would you give me a call and give me the address for your home so I can come see it? I have done several deals this way if I've had a good reason to believe a property would be a good match for serious buyers. I then only ask for the OTS contract when a date is being set for the showing and names are put on the agreement.