Let's just limit this to the United States, because from my understanding and experience haggling for everything, not just food, is much more common and commonly accepted in other parts of the world.
So, in the United States, do you ever haggle over food or meal prices?
I know some consider it déclassé, but I also know that many of us do it (myself included), so please feel free to share.
Personally, I've done it at local Farmer's Markets, county fairs, coffee shops (incl. Starbucks), and your typical neighborhood ethnic eateries, incl. many many Chinese restaurants of all stripes.
No judgments please, let's just share stories and experiences. Because people also consider picking your nose déclassé, but I know I do it, and I proudly admit it.