Fair enough on the personal decision part. I'm less interested in telling people what to do and more interested in whether the premise ('nicer things = happier') actually tracks with how human satisfaction works. The research suggests it often doesn't, which seems worth knowing regardless of what you choose to do with that information. [1]
I would recommend the recently published book The Art of Spending Money by Morgan Housel, or check out the interviews he's done in recent months on it:
It's not about being frugal or cheap or spendy, but on recognizing human psychology and what actually brings most people happiness. See also the 85-year Harvard study on the topic:
