They're pricing at the point of pain, not maximizing efficiency. There are few enough companies (what, like, 3?) that own the majority of the brands so they don't even need to collude to figure out that they can all hover around "as high as we can get away with" together.

I've been nursing a minor Coke Zero addiction for years but usually get the store brand which is close enough at half the cost. For whatever reason Coke Zero itself dropped in price by about 30% recently but that's apparently not nationwide.

It really kind of blows my mind how much of that people drink. I'll get a 2 liter bottle that will last days and then I read about people going through entire cases of Mountain Dew Insane Flavor Combo Super Bacinator Blast in a day and it's like my god that's like 4000 kcals of corn syrup.