Random thought

In some marginally technical fields, it seems like there should be more of a market for technical advisors or professional shoppers. So if one is buying a car or a computer or some other gizmo, if one doesn't know much about the field, rather than going to some dealership or big box store and relying on biased advice of the salesman and probably not getting the best deal you can, why is there not some other independent person whom you could tell them what you want/need, talk over what that means you're (probably) getting, give them a budget range, and commission them to go find the products that you desired at a reasonable price?

I realize there are people who do do this (for example in technical gadgets or fashion), but it would seem like something that people could advertise their services for and, in time, would largely do away with the need to deploy salespeople (and finance people who in effect work against the salesperson and the consumer). Presumably the reason that stores and car dealers do this is that there are profit margins to be had in pushing products associated with technical products, but if there are small and pervasive armies of professional buyers who are aware that most of these products are worthless or, at best, worth less than they will be charged, these margins will be reduced or even eliminated. At that point, the sales people might have jobs as independent contractors who are genuinely working for consumers rather than employed by the company to push a product.