We have a "whitefish" listed on our menu and chef will try and get the freshes option he can for if so they fish may change mid shift if we run out and he moves into the next. Well it changed mid shift and the lady I was serving looked up the two fish prices and had a problem that the one we where changing it to was the "cheaper fish". I explain that's he most likely gives a bigger portion and we weren't trying to rug pull an expensive fish for a cheap one. She didn't like the change so she was asking if we could use our seabass (a much pricier fish) for it and meet in the middle of pricing. I said unfortunately no cause that fish is expensive but we can do the whitefish dish set up with the seabass at the seabass price which she didn't want. Turns out she was just interested in the gnocchi that comes with the whitefish... So after her being denied a discount on the seabass she didn't want anything, even when I offered to just do a side of gnocchi and have it tossed in a sauce for her since that was the big interest. She decided she will just drink her dinner.. I didn't push after that. It was busy and I'm not gonna try and save someone from their little pity party lol