Overuse of library

Hi all, I’m really struggling with a specific concept and would love input/advice. I listened to the Harry Potter audiobooks for the first time via my local library last year. I really enjoyed them and have been thinking of re-listening to them. I know it costs the library more for audiobooks and often have a specific number of check-outs a book can have for a specific price point. I feel bad checking out the same book multiple times because of how much it would cost the library. Should I just buy the audiobook outright so I can listen to it whenever I want? I know using the library and their resources is also good overall and helpful to maintaining the library funding but I’m worried about over-using the resources or possibly even being a financial burden that’s kind of unnecessary, since I’ve already listened to them and recently.