I love this idea!!! I also read a lot and I also own a shitload of books! Not on kindle or audible but physical ones.. Last year I discovered 2 second hand online book stores where me and my boyfriend ordered about 150 books for probably 200 Euros.. an incredible price! However, even though I read about one book per week I could probably read several years until I’ve finished all of those which I already own. And I always struggle to pick the next one! I will think about your challenge and probably also go for it! Thanks for the inspiration!