What this poll might have been helped by is some option as to whether you buy adventures or not. I buy almost every official rulebook, but I buy zero adventures (I have access to quite a few because some people I play with have them shared with me via Beyond but that's another story). I'm just not interested in "Adventure Path"-style writing from WotC. Like, every time, it's just... not very good. Rarely terrible either... but not very good, like I could do better with the same ideas/material. I don't want to derail on that too hard, but it's like, a major influence on what D&D stuff I get (I don't find this to be true of all companies or all games). I will probably get the 17 short adventures book because most "A number of short adventures" books tend to be, well, pretty good, even if other adventures from that company aren't (I mean, assuming a certain level of basic competence). And they often actually get used - I still use "a bunch of short adventures" books from 1E AD&D for example, thanks to Dungeon World. The WotC one also has some exciting authors, and even if 50% of it is "meh", then that still a bunch of good stuff. Whereas if 50% of an AP is "meh", then the whole thing is kind of ruined.
I should add that I also largely buy from Beyond re: official stuff.
I do have some third-party stuff, but I tend to only buy things which can easily be integrated into Beyond. I.e. magic item books, very discrete systems books that don't require modifying the core game rules (or adding to them in a permanent way), monster books (to some extent), and so on.