When it comes to plumbing fixes or home redesigns, it makes sense to shop around for the best price. But what if you need hip replacement surgery or a colonoscopy? Would comparison shopping for health care be a good idea? Advocates say it’s a great way to control health care costs for both providers and patients. And now, there are multiple services aiming to make that easier, such as Castlight Health. This newly proposed search engine that would allow consumers to search for nearby doctors and, based on their insurance coverage, compare the prices of certain procedures. According to a recent study conducted by Mercer, a human resources consulting firm, people who are more aware of health care costs, spend less in the long-run. But how workable are services like this? And does it make sense to treat health care like other goods and services?