I can certainly hear the difference between MP3 320kbit/sec and CD's LPCM even on my phone which will drive good headphones (although I do use MP3/320 on that for space reasons and the audio limitations of portable headphones) let alone on a dedicated system. So I buy CD's which are cheap enough given their long lividness and the number of times they are played. Out of habit I rip for other use to WAV, so still LPCM as the original CD was, but I agree with the comments regarding FLAC.
Neil Young has some interesting, perhaps fanatical, views on this (expressed, for example, in his auto biography
Waging Heavy Peace and other places) regarding MP3s as being "terrible", but also regards CD's as a medium less than what should be aimed at (so, his yet to get up and running properly Pono download service).
I very rarely buy paper books these days and with eBooks I am guarded as to what I buy and at what price (usually specials or freebees now) as they seem expensive to me per use given they are usually just read once and are not supposed to be loaned/sold (on both those points unlike CDs and movies, for example). But I don't buy many these days as I have been reading and collecting eBooks for many years now so have a reading list of books on hand of unsurmountable size
. I make sure I have an archive copy of every book, not limited to any one device or reader application, and that is the copy I use.