Have you ever heard of being charged extra for mayo in a restaurant?

A friend just told me about an experience she had where she ordered a burger and fries to go from a restaurant near her job. The cost was 15 dollars, which she thought was a bit high, but she paid it and after tax and tip, it was close to 20 dollars. She requested a side of mayo, because she doesn’t use ketchup. When she got back to work and looked at the bill, she saw that they charged her .75 cents extra for the mayo.

She reviewed it online and mentioned the cost and the extra charge for the mayo. She felt it was excessive to be charged extra for it. The owner addressed the review and talked about higher costs for food and overhead (rent, utilities, etc.) but didn’t specifically mention the mayo cost.

I’ve never been charged extra for a condiment. I know some Mexican places will charge extra for guacamole but I don’t really consider that a condiment, it’s more of an appetizer.

Do you think it’s excessive to be charged extra for mayo? Is this a thing now? I don’t eat mayo like that and I’m not usually ordering burgers in restaurants, so it’s not been something I’ve encountered.

They say if you can’t afford to eat out, you shouldn’t, and I can afford it but when I hear about stuff like this, it makes me less eager to eat out.