You know the answer to that. They'll pay whatever is asked until they can't. Most people aren't going to modify their spending habits proactively. If increases in the cost of living outpace their ability to increase income, unless they make a lot more than they spend, what used to be living within their means becomes living beyond their means unless they voluntarily make the necessary adjustments, and how many people are smart and disciplined enough to do that quickly?
Fast food is an overpriced, unhealthful, first-world luxury. Maybe you can do yourself a favor and just drop it from your life even before prices get to where you have to.
Were you aware that
the Supersized guy died of cancer recently? I don't know what part his month of self-abuse played in that. He was also a drinker and had liver problems.
Besides eating overpriced fast food, Americans living paycheck-to-paycheck still have gym memberships, designer clothes, spa days, regular hair tinting, the latest smart phone, gaming consoles, mani-pedis, and go bar hopping. They go into debt with destination weddings. They have student debt, car payments, and credit card debt to the limits of their budget today, and then something changes, and they're financially threatened.
I was watching the news about how expensive daycare has become in the States. One young couple, both nurses, was spending one paycheck on daycare, so, since she made more as a nurse anesthetist, he became a stay-at-home dad. Their second child was less than a year old. It seemed like they couldn't afford two children now. Presumably, they thought they could afford a second child a year or two ago, but that was then.
The trick is to make necessary modifications there as soon as possible. Cut back before incurring excessive credit card debt until you can't get any more and then go under. Maintain a cushion between where you are now and insolvency. Severely restrict discretional spending until you have some savings. Eat out less. Drink out almost never. Quit cigarettes.