I'm looking for a way to use Amazon S3 as the Media Library for this website. Essentially, I would like it so my media files (photos mostly) will be stored in S3 by WordPress, bypassing the hosting server's drives for permanent storage. I use a hosting service that charges on a pay-for-what-you-use basis, and their storage fees are quite a bit higher than Amazon S3's.
I'm already using Amazon S3 as a CloudFront source and as storage for larger files, like audio recordings, so I'm already paying twice for storing the files in the Media Library. However, my users require the convenience of the WordPress Media Library, so uploading to S3 and then manually hotlinking the files is not really an option.
Does a method/plugin already exist for doing something like this? Would I need to write my own plugin? Is this even reasonable?