"想讨便宜的顾客" can be translated into English as "customers looking for a bargain" or "customers seeking discounts/deals".
"Looking for a bargain" emphasizes the desire to find something at a lower price than usual.
"Seeking discounts/deals" highlights the intention to obtain goods or services at a reduced cost or with special offers.
Both expressions accurately convey the idea of customers aiming to get a good deal or save money.