Being doing customer service a bit, I really dislike customers that criticize our goods/service just to reduce the price.

Like in the market buying vegetable.

Buyer: "What is the price"
Seller: "5.00 ringgit"
Buyer: "What... your vege, spoil one, not fresh one, how come so expensive... 4.00 ringgit lar"
Seller: "I am going to be as nice and polite as possible..... Go fly kite...... please...."