There used to be a relatively popular post here on HN a few years ago with links to multiple similar blog posts where authors collected list of the best value (in their opinion) things and activities. For example, I remember an author argued that hiring a tutor on any new activity is money well spent. Or buying certain items like Aeropress, etc
Thank you
idk what exactly you're looking for, but it probably contains the acronym BIFL (buy it for life) in the comments.