I care enough to make changes when they are relatively easy (i.e. fit reasonably into my lifestyle or timely (e.g. when it’s time to get a new car). In recent years, I
racked up 30,000 miles in a 94 SUV for a year and half while pursuing a long distance relationship, and now that we’re in the same town, we are doing a lot of traveling. I’ve also done two years without a car (as an adult), and more recently subscribed to wind generated electricity , because my bill wasalready cheap.
So, I would spend what I felt like I could afford to reduce it. I wouldn’t be much more interested than an eyeballing of the results, since that’s about as much effort as I put into watching my checking account.
After experiencing much angst over these kinds of issues, I have to say that I no longer allow them to take precedence over my own happiness.