Not to make excuses for this, because it's not fair to customer, and it's bait and switch pricing IMO... but I understand how you could get there. Sorry this is long winded.

Based on the "thank you for your support", and their clearly not having a legal department, my guess is this is a small business. Prices have swung so wildly in the US in 2025 it's basically unmanageable without a dedicated team.

For example in August of 2024 the price for a lb of coffee according the US Bureau of Labor Statistics was $6.31. In August of 2025 it was $8.87. That's a 40% increase in one calendar year. https://fred.stlouisfed.org/series/APU0000717311

Eggs were $3.20 a dozen in Aug. of '24, but by March of '25 they were $6.22 that's a 94% increase in 7 months. Then they crashed back down to 3.58 (a 42.44% decrease) by August. https://fred.stlouisfed.org/series/APU0000708111

Now for the sake of a practical example, here's a pretty typical menu for a family diner in New Jersey. It's 11 pages. Maybe 20 items per page. Each item may have 5 to 10 ingredients.
https://www.pomptonqueendiner.com/menu_main/

• You can either try to recalculate all of that every week or two based on tariffs, inflation, bird flu, etc... then reprint and spiral bind 50 to 100, 11-page menus (technically 6 laminated front and back).
• You can overhaul your business model to be leaner, but maybe lose some customers.
• Or you can try to guestimate a number you think you and your customers can live with and distribute your gains and losses across the whole menu and reprint one page with a fee (hopefully) once.

It's a shit sandwich. I don't think this was a good solution, but I don't think a lot of small businesses (or consumers) have good solutions these days. McDonalds has a procurement team, and can lock in terms with their vendors a year in advance. They can update prices on digital menu boards on the fly. They can handle these things pretty easily. Your local greasy spoon may not.

I'd personally weigh whether I think this place and the people who run it are maliciously trying to exploit me or just find a way to get by selling cheese burgers and eggs in this economy.