Earlier quoted context omitted.
Your definition of irrational is not everyone's. I suspect you buy things other people would consider irrational, yet you buy anyways. Does that make you irrational? Or do different people have different utility functions? People buy what they want, not what you think they should.
Nope, its not that subjective, and not about what I think or don't think I should, food is a product category that is fully rational to buy from and its one of the reasons its prices tend to be more stable and is strongly corelated to the hardships of the production chain, not all foods but certainly a lot, certainly the most basic ones (e.g. potatos). Just like buying a smartphone is a more rational choice than buyi…
Sorry, human utility functions, which drive pricing, are subjective [1]. This is basic economics. Different actors have different values - if there were some mystical "rational" rule to drive prices, it would be the same for all people. That some people value different things differently would imply that what is rational for one person (thus they choose one ordering) must be irrational for another (since they choose a different ordering).
Some people buy Goop because it makes them happy. That is all that is needed. That you do not does not make their purchase irrational. That is a misguided way to judge them and their preferences.
>and its one of the reasons its prices tend to be more stable
No, it's the other way around - people ten to buy more of the foods that are priced stably since they can plan. Many foods are wildly unstably priced, and as such cannot be planned around, so are more niche.
And this happens not just in food, but pretty much every type of good.
>certainly the most basic ones (e.g. potatos).
Potatoes are historically more volatile in pricing compared to other food stuffs [2] (you can use the site to check lots of goods, put each in Excel, compute volatility). So your claims are contradicted by evidence.
> predictable but irrational
Define a rational purchase. Be sure to address individual utility functions.
[1] https://en.wikipedia.org/wiki/Utility
[2] https://www.in2013dollars.com/Potatoes/price-inflation#:~:te....