My husband and i want to buy a 2007 durango?

the salesmen is so annoying though-he wants us to buy the 45,000 one instead of the 27,000 one and he wont give in. He keeps saying yeah that one is nice but look at this one blah blah. then he wont give us a fianl number in what they are giving us on trade in. what can we do? we really want the durango but dont want to get the run aroundwith him on financing etc.? thanks