Maybe you haven't hit on the right house yet with this buyer.
I had one buyer who always lopped off at least 10% from the list price, no matter what, when he went to make an offer - even though I showed him those offers were unrealistic .Needless to ssay, he never got those homes......he rarely got a counter offer, either. Then a wonderful thing happened - he saw a home he really fell in love with. He offered within 3% of the list price, and bought it. At last!
Of course, miracles don't always happen, though!
I am nnot sure how long you have been working with him thus far, but why not set up a timeframe, and if you still find he isn't being reasonable with his offers, then cut him loose, and move on. He either isn't motivated to buy, or he has read too many "How to" articles advising buyers what to do.......incorrectly!
Prudential NJ Properties