Reading the other comments, this seems to be more of a cultural thing than something based on facts. Ibuprofen seems to be taken in more serious situations. Personally I’ve never had it so I’m not sure. Paracetamol is more of a casual thing here. Many people, like me, would only take it when very ill. But I’ve definitely had a few classmates or colleagues who just take paracetamol whenever they have a slight headache or something.
Honestly, however much I want to pretend to be better than that, I think it does work on me. Obviously not on a conscious level, I know how numbers work, but some part of my monkey brain sees the 1 instead of the 2 and therefore concludes that it must be way cheaper. It’s a feeling that no amount of facts is going to disable. And in the end many purchasing decisions aren’t based on a full analysis but on feelings.