In my dream, a diner from the high-class side found out about the conspiracy and demanded to be allowed into the other part of the restaurant. After meeting much resistance, he finally got a table and was waited on by the manager of the restaurant herself. She proceeded to make his experience there a living hell - by making him jump through hoops to make his order, laughing in his face when he made special requests, and serving him burned, badly-seasoned food. The reason? The upper class diners were not treated badly because they were on the wrong side of the restaurant, or even because they had money. It was because they treated people of lower status like inferior beings, and got exactly the treatment they deserved.
While dining on the high-class side they were paying for the knowledge that they could afford something other people couldn't, even if the quality of what they were paying for wasn't worth the price. It wasn't about having a superior dining experience: it was about appearances and flaunting power. In my experience, that is the motive behind many of the expensive products and services that people buy or covet in our society, believing them to be better simply because they cost a lot.
One last lesson from my dream last night: as different as the two versions of this restaurant were, there was one thing they both had in common. They shared a bathroom. I still haven't figured out if that means anything, but I'm willing to bet there's something very clever in that.