I’m glad to see that someone recommended BookBub; I get a lot of cheap books that way.
Otherwise, I borrow from library systems. I read 2-3 books a week, and I could never afford to buy that many. You can check to see which public libraries allow out-of-area users to have library cards. Many do, especially if you’re willing to get a card that’s good only for ebooks. I have regular library cards for 3 counties near me in California. It’s a regular card, but I check out only ebooks.
New books come to libraries on Tuesdays (I find that some libraries add the record on Monday nights). I have a list of authors I like, and every now and then I look up either the author’s website or their Amazon site to see when their next book is coming out. Then I use a text messaging app to schedule a message for my phone on the day their next book comes out. Because I have so many holds, the long wait doesn’t bother me as much.
I tried the trick on my Kindle to return a book a day late, and it worked.
eta: I forgot to mention that most public library websites have a “new books” page where you can see what’s come out recently.