There are lots and lots of great books you can get for your reader legally without even paying anything.
At the moment I have some 10 books in my "to be read" pile.
When I was younger I used to visit library every week to get fresh pile of books to read. The books used to be very cheap here, yet I was never rich enough to support my reading "habit" by buying books.
So I became an opportunist. I never went to the library with a goal "I am going to get book XY by author ZT and I will not take anything else". Of course, sometimes you find an author and you try to get his next book, but it does not mean that you can not check out another 10 books in the meanwhile. I personally try very hard to get as many of Terry Pratchett's books as possible.
Try to approach the problem of getting books from an angle "let's see what I can get" instead of "I do not want anything except books from this list".
I am not suggesting that you start reading Shakespeare or Harlequin romances, but try to have a look around this forum part:
https://www.mobileread.com/forums/forumdisplay.php?f=26
You might start with
https://www.mobileread.com/forums/showthread.php?t=44129 (it looks that at the moment Mr. Morrison's page is down, but try later. The books are worth trying)
Go to the Sony store. They have about 7 books for $0, you might like some of those.
Also have a look at our e-books. Not everything there are old books.