BUT YOU KEEP CONVIENIENTLY LEAVING OUT THE SERVICE PART!
Unless you are in a burger joint or some hole in the wall people typically expect better service. Now before someone starts in on a rant about how you should get good service no matter where you go.....here's the difference. in a nicer restaurant (where prices ARE HIGHER) the servers can often (not always) but often have more on the hands than at smaller places. they are expected to look the part of a clean friendly server. they usually have more demanding customers. they may have more tables, more drinks to fill, as they have to fill water and other drinks. they may have to deal with a bartender to get mixed drinks, they may have to bring you bread. They may have to serve you wine. They are more likely to be serving you dessert. In more expensive restaurants, the standards are higher and thus the burden of duties becomes higher on the server. THAT is why price makes a difference. they are dealing with sorts of issues that servers at Joe Blow's restaurant probably aren't having to deal with.
In the end it all comes down to service, and the service changes depending on what type of place you are at. Just look at Disney! We pay more and return to them because of the service. There's a theme park not 45 minutes from my house but I haven't been in ages because it's not the same. but, it's not Disney, so I don't expect it to be the same. that's why I am ok with Disney's prices being high, they deserve it, because they work harder at what they do.