I could produce a long list of things I will not economise on. I did something similar when I stopped work when my first childe was born. That was in 1971.
But faced with the rampany inflation of the early/mid 1970s, it was amazing how quickly these 'non-negotiable must haves , quickly became 'can do withouts, when the pips really squeaked.
This is why I am not posting a list of things I will not economise on, and I have one. But although we are fortunate to have a very comfortable retirement income and I cannot see us finding money very tight - yet, yet, yet, I am just not prepared to offer any hostages to fortune because in the present fraught ecomonic and political situation, anything could happen, - and I am not going to get caught out twice.