I am wondering why on earth you think this. There are plenty of people happy with the junky knives you can buy out of a bucket at gas stations, would you agree if one made the argument "you shouldn't have to pay more for a quality product"? You seem to think all a merchant does is offer stuff for sale at the lowest possible prices, that is all you are "paying for". What about having knowledgeable staff that actually cares about the products they sell and can intelligently answer questions and guide you to the right product? Do you think well trained, courteous, and knowledgeable staff are easy to find, train, and retain? I have managed retail stores and I assure you they are NOT. And what about their pay, do you want to deal with people making a minimum wage or people for whom doing this job is a profession in which they take some pride?
Service is something the merchant is providing you, it has costs like anything else, to some extent at least you get what you pay for. If it doesn't make any difference to you then by all means buy from warehouses etc and pay the lowest prices possible. But it makes no sense to say something (like service) is worthless when clearly there are people willing to pay for it.