Did you overhear them say they ordered those particular things because of the prices of other things on the menu or are you just assuming?
Sorry to butt in with this, but the comment just struck me as making assumptions about another person's order when it could have just been "they like to eat expensive French fries". Perhaps they're like me and it's a nice small meal that isn't incredibly greasy. Now, if you did hear them say they ordered as they did because everything else was too expensive, then ignore me and my apologies

. Not trying to be rude.
It'll be interesting to see the prices when I'm there in a week, that's for sure.