edit: hah, someone's done the legwork: https://efficiencyiseverything.com/calorie-per-dollar-list/
No drinks though. Looks like soda from a $2 2L bottle comes in at about 500cal/$, much lower than the leader in that list. Not sure how cheap one can get soda elsewhere though (from fountains etc).
Most of human history was lived by people with some amount of malnutrition. It's almost a default state of being alive. It's only since the broad cultivation of the Potato and after that, green revolution that allows us to grow enough food to technically feed everyone (and then throw half of it away because god forbid we help people survive rather than build a system that incentivizes dragon hording)
Obviously it's easy to speak from my perspective where I'm fortunate that I don't have to worry about accessing food.. but even when confronted with that my position remains unchanged. Maybe if you were arguing about healthy/neutral drinks I would feel different, but I've had enough people in my life develop obesity and diabetes from addiction to soda to regard it as marginally better for you than alcohol and tobacco.
I hope I live long enough to see society in this country start revolting against HFCS/sugar and excess sodium in our diets, it's death by diabetes and heart attacks/strokes.
In comparison, fast food like a 2-liter bottle of Coke or Pepsi provides about 450 calories per dollar, while a fast-food hamburger provides about 100. While the corn syrup lobby and fast food industrial systems are strong, they're not even close to being a cost-effective way to feed yourself.
Actually I'm starting to like this idea of banning sugar and maybe some other ingredients, would get rid of a lot of garbage in our diets.
Also, peanut butter is highly nutritious, even with some amount of added sugar.