This feels like a discussion of nuance; relative improvements. Of course, the daily Starbucks latte is the most-often quoted symbol of anti-Mustachainism. Making your own coffee at home with store-bought beans or pre-ground coffee is so much cheaper, it's laughable. I will occasionally see a coffee shop while driving, with some time on my hands, and think,"that looks good" reflexively, then get the cold sweats when I think about how my own coffee tastes better than most coffee shops (at least for me), then I smile and drive on.
To fine tune beyond this for lower cost seems to me to be a philosophical choice. If making the cheapest coffee beans possible tastes just as good, then of course, use them. But if it doesn't, then what's the point of it? Similarly for switching to tea. If you enjoy coffee and tea interchangeably, then of course it makes sense. I do drink tea sometimes, after I have had my coffee, but wouldn't consider it an even trade-off. I'll have herbal tea in the afternoon when something hot sounds good. But coffee is not nutritive in any way. It is far from a necessity of life. It is only used for enjoyment. I get a lot of little moments of joy from drinking coffee, and would be careful about chipping away at little compromises in the experience, since the experience is the only point. I think of my own (relatively spendy, as I sometimes buy more premium beans for a splurge) coffee use as a pretty frugal great thing in my life. It all depends on what we're trying to optimize: financial benefit, or experiential benefit.
