Restaurant prices aren't a secret. I just checked places in Portland and the most expensive burger I could find was $15 and that came with fries, and that was the most expensive one on the menu. This is a meme joke and is exaggerating to be funny, don't confuse that with reality.
Have you paid $22.50 for a burger on its own? I find this post odd because I live in an expensive city where you can easily see plates over $30 but even at those places, their burgers are the much cheaper option and still often include fries or have a $2-3 upcharge to get fries.
Or if you had a logical thought in your head, you found a person so unfamiliar with such a place, they asked publicly despite knowing that douches on the Internet are extremely common.