I'm having a terrible time resisting new ebooks. I have more than 10,000 titles listed in my Calibre, and 7836 in my kindle library. There's no way I will live long enough to read everything I have already downloaded!
Two things that help:
* A Chrome plugin called "Library Extension" shows up on webpages at bookstore sites (including Amazon) and tells me whether my local public library has the book whose page I'm viewing. This helps me refrain from purchasing a book that I can get from the library for free:
https://www.libraryextension.com/
* The website ereaderiq.com has price history for many ebooks, which helps me determine if the current price is the best ever offered and if that low price is likely to be repeated. (The downside is that when I can see that a price is the best ever, I usually buy the book, even when I know I won't be reading it right away!)
I'm trying to persuade myself that it's better to spend full price on an ebook that I will definitely read right away, than to spent the equivalent amount on 10 ebooks that I might not get around to reading.