Wiktionary
comparison shopping
n. The act of comparing prices of something in advance before shopping for the best bargain
Usage examples of "comparison shopping".
Yet he bought a new jeep wagon only every ten years, owned one suit, and was notorious at Pineridge's Acme Supermarket for spending as much as three hours comparison shopping to save eighty cents on one order of groceries.
Jason's an appliance freak, and he wanted to describe his comparison shopping for a new water heater in detail.
Did some comparison shopping and purchased two nonstop tickets to Paris.