Such a customer is a cheat, imposter, who is wise in fooling others.. They are the dishonest shoppers, where their aim may be to lift or cheating the salesman while he is busy in presenting. Being dishonest, they go on asking all the possible questions let the product or product at least rate. There is no guarantee of saying inspite of price reduction and all the concessions being given. Instead of salesman persuading these customers, they persuade to grant maximum concessions. They quote the rates prevailing in other shops and threaten quit if his price quotations are higher the other shops. Whether they are in group or individual, they have an possible tricks to life product or products.
It is really a tough task to handle such imposters or cheats. He should justify his stand in terms of quality and prices as opposed to competitions. That is, should know what competitions are doing in such products. He should be quick calculator or manipulator to present himself as best in terms and conditions of sale. He should keep eyes on each customer to avoid shop lifting.