I know that lady, and all the other ladies, and gentlemen in CP.
Never had a problem with the ladies or gentlemen, even though I may be just browsing.
Put yourself in their shoes. What do you think of a customer who tries to ask for a 45 cents discount? ("trying my luck") How would you view such a person? Sure, we want them to be "professional" even though we might not be the modell customers.
Sales people are people with feelings. Sometimes we just might be asking a little too much, especially when our own behaviour may just be less than exemplary.