>I can't concentrate when reading on a computer screen
Same here. I buy physical copies of larger books as well as books which I know I'll be referencing a lot. Smaller books and books which I'm only reading as a means to understand some other work I'll usually just snag a pdf. It can get a little expensive to keep buying books, though, so used stuff is definitely a good idea, but I think the cost is worth it if it's letting you read more than you would only on your computer.
If you haven't heard of them, AbeBooks.com is a pretty good international online used bookseller. Their selection is better than you'd think it'd be. I've found some pretty niche books on there. Radical Reprints is also really cool. They're a leftist publishing group that print a lot of really neat and hard-to-find leftist literature with microscopic profit margins (what profits they do make are donated to leftist causes/mutual aid networks/etc.) so that's another pretty affordable option.
>should I try to get the absolute best translation and publisher or is does it not matter what edition I get as long as I freaking read something?
If the really good edition is ridiculously expensive, just get the inferior version, the difference in quality is almost never worth shelling out an extra $50 for. That being said, there are occasionally important differences between translations, especially if the translation is from a more difficult language to translate, like German. Sometimes the better translation can be easier to read (e.g. Michael Inwood's new translation of The Phenomenology of Spirit, which I've heard is appreciably clearer than the standard Miller translation, but which is also $100 more expensive, so fuck that), or sometimes it can even alter the meaning of the text (iirc, some Lacanians dislike James Strachey's translations of Freud's work, arguing that he de-emphasized the importance of language in Freud's work). In my experience, edition doesn't really matter, unless there were big differences between editions, which is sometimes the case, but not usually. More superficially, some editions have nicer typeface, or better paper, but I've never seen a typeface so ugly nor paper so blindingly white that I couldn't get used to it in twenty pages.
This is all to say that translation does matter, but nine times out of ten isn't worth spending money over. It's better to read a worse translation than to go broke getting the best of the best from some price-gouging academic publisher. Better translations are nice, but not at all necessary.